What is the detection principle of the rapid nucleic acid detection kit?

The kit is to configure the various raw materials that need to be used in PCR replication and amplification in advance, and then the medical staff can greatly save the configuration time when making the diagnosis. At the same time, the conditions (temperature, time, etc.) used by the kit also need to be explored and explored by the developer. Continuous optimization, testing and verification are required to ensure the accuracy and precision of the kit and avoid misdiagnosis and missed diagnosis. In the case of (false positive and false negative), a standardized novel coronavirus nucleic acid detection kit for clinical diagnosis can be obtained subsequently.

1. What is the rapid detection of new coronavirus nucleic acid?

As we all know, rapid nucleic acid testing is currently the “gold standard” for the detection of new coronaviruses, and it is also a direct evidence for judging whether there is a new coronavirus in the subject. The new coronavirus is an RNA virus, and the specific RNA sequence in the virus is a marker that distinguishes the virus from other pathogens. After the emergence of the new type of coronavirus, Chinese scientists completed the analysis of the complete genome sequence of the new type of coronavirus in a very short time, and discovered the specific nucleic acid sequence in the new type of coronavirus. If the specific nucleic acid sequence of the new coronavirus is detected in the patient’s sample, it indicates that the patient may be infected by the new coronavirus.

 

 

2. Principles of COVID-19 rapid detection kit

Most of the rapid nucleic acid detection kits use the fluorescent quantitative PCR method. The genetic material of organisms is divided into two types, DNA and RNA. DNA has a double helix-like structure, which is more stable, while RNA is a single-stranded structure. Coronavirus is an RNA virus, which is easier to mutate and adapt to the human body. The most important way to confirm whether a patient is infected with the new coronavirus is to detect whether the genetic material of the virus is present in the patient or suspected case.

However, the amount of RNA that can be extracted in patient samples is limited, so a method is needed to quickly detect the nucleic acid content in virus samples. Fluorescence quantitative PCR is a new type of quantitative test technology launched by an American company in 1996. It uses fluorescent dyes or fluorescently-labeled specific probes to label and track PCR products for real-time monitoring of the reaction. So, what is PCR? PCR is the polymerase chain reaction, which can greatly increase the trace amount of DNA. The process of fluorescent quantitative PCR is to use enzymes to generate DNA from RNA through reverse transcription reaction, and then use DNA as a template for amplification. At this time, more detectable fragments will be obtained.

At present, the rapid nucleic acid detection kits that use the fluorescent quantitative PCR method in China mainly have the advantages of high early diagnosis sensitivity, strong specificity, fast detection speed, and high popularity. For example, the new coronavirus nucleic acid rapid detection kit launched by Aisen Biotechnology Company, this new coronavirus nucleic acid rapid detection kit has obvious advantages of convenience, high sensitivity, strong specificity, and fast detection time, which greatly improves the new coronavirus Inspection efficiency can be widely used in clinical, CDC, and customs inspection and quarantine.

Common types and development prospects of magnetic beads

Magnetic beads are the main tool of new nucleic acid extraction technology. Magnetic beads have the characteristics of monodispersity, high specific surface area, good dispersibility and resuspension, faster magnetic response, better water solubility, and more active functional groups. They can form a “quasi-homogeneous” reaction system. It can combine, react and separate with the target fragment with great efficiency and specificity. Under the directional control (automation) of the external magnetism, the target molecule can be separated from the complex biological system, soil, water and other samples through adsorption, cleaning, elution and other operations. Next, I will share with you the common types of magnetic beads and their development prospects.

Common types of magnetic beads

1. Unmodified magnetic beads

The magnetic core is Fe3O4 magnetic group, which is first coated with derivatized silane, and then coated with polymer. In the early days, some manufacturers would directly mix Fe3O4 and polymer, grind and sieve them out, and even mix Fe3O4 powder into the beads during the emulsion polymerization process. However, the magnetic beads obtained by these methods have some problems. For example, the exposure of iron (magnetic leakage) will affect the experimental results of DNA polymerase users. Iron can reduce the activity of the polymerase and adversely affect many cells. In order to improve the stability of magnetic beads and expand their application fields, scientists add different materials to the magnetic beads in different proportions, such as polystyrene, cobalt dioxide (non-paramagnetic), agarose and so on. Generally speaking, a polymer outer layer is added to the surface of the magnetic bead, or a relatively stable outer shell such as silica is added. The purpose of coating is to protect the inner core of the paramagnetic bead and prevent it from being oxidized; in addition, this These coating materials have good biocompatibility and are easy to couple with various functional groups.

2. Magnetic beads with universal specific ligands

This type of magnetic beads captures a group of target molecules and is versatile. It is often used for nucleic acid extraction and purification in scientific research and molecular diagnostics, and purification of PCR amplified products; it can also be used in high-throughput second-generation sequencing platforms, such as Illumina Sequencer blunt-ended fragment DNA screening, etc. In short, through various chemical modifications and chemical reactions, hundreds of general-purpose specific ligand magnetic beads with different functions can be obtained, and the application fields are very wide. It can be used not only for nucleic acid purification, but also for protein and polysaccharide purification and immunoassay detection. In addition, this type of magnetic beads is also widely used in modern biomedical chemical technology and research for the screening and delivery of biochemical macromolecules and small molecule drugs.

3. Magnetic beads with specific recognition groups

This kind of magnetic beads can enrich and separate target cells, and can also separate out hybrid cells by specific adsorption (using magnetic beads with specific antibodies to non-target cells); in some specific experiments, such as positive in molecular cloning systems For cell separation, the vector encodes the cell surface marker protein, and the successfully transfected cells can be separated by using magnetic beads coupled with specific antibodies (for the cell surface marker protein expressed by the vector).

The development prospects of magnetic beads

In recent years, magnetic beads have been gradually applied in fields such as biomedicine, cytology, and bioengineering. However, the magnetic beads and magnetic bead series produced by foreign companies still have a great advantage in the application market. It started late in China, but in recent years, a number of high-quality companies have also emerged to produce magnetic bead products, such as Aisen Biotech. High-sensitivity, high-throughput, and high-efficiency magnetic separation and purification technology has shown broad application prospects in the biomedicine and clinical diagnostic markets. The huge market demand will inevitably drive domestic companies to develop and produce world-class magnetic bead products. Let us wait and see!

The common types and development prospects of magnetic beads are generally introduced as described above. Aisen Biotechnology produces nucleic acid extraction products with nano-biomagnetic beads as the core. If you have relevant needs, please call for consultation.

Basic performance and applicable fields of various magnetic beads

Magnetic beads are important equipment used in biological immunology. They have super paramagnetism and can quickly accumulate in a magnetic field. After leaving the magnetic field, they can contribute to the uniform dispersion of magnetic separation. By coating the surface of the magnetic beads with specificity Antibodies, receptors, etc., are used to separate and purify the target in the sample, and have been widely used in many fields such as immunoassay, nucleic acid separation and extraction, and cell sorting. There are many types of magnetic beads, and their basic performance and applicable fields are also different. Next, the editor of Aisen will share with you the basic properties and applicable fields of various magnetic beads.

Basic characteristics of various magnetic beads

1. Basic performance of carboxyl magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) Density of carboxyl group: about 2000 nmol/mg

(4) Surface potential: about -35 mV

(5) Concentration: 10 mg/mL

2. Basic performance of carboxyl magnetic beads (low non-specificity)

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) Density of carboxyl group: about 1000 nmol/mg

(4) Surface potential: about -35 mV

(5) Concentration: 10 mg/mL

3. The basic performance of amino magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) Density of carboxyl group: about 600 nmol/mg

(4) Surface potential: about 30mV

(5) Concentration: 10 mg/mL

4. Basic performance of mycostreptavidin magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) SA load: 60-90μg/mg

(4) Surface potential: about -35mV

(5) Concentration: 10 mg/mL

5. The basic performance of protein A magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) SPA loading capacity: 70-75μg/mg

(4) Surface potential: about -29mV

(5) Concentration: 30 mg/mL

6. The basic performance of protein G magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) SPG load: 70-85μg/mg

(4) Surface potential: about -26mV

(5) Concentration: 30 mg/mL

7. The basic performance of protein A/G magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) SPA/G loading capacity: 70-85μg/mg

(4) Surface potential: about -26mV

(5) Concentration: 30 mg/mL

8. The basic performance of nucleic acid extraction silicon hydroxy magnetic beads

(1) Electron microscope size: about 1μm

(2) Magnetic content: 35%-45%

(3) Surface potential: about -26mV

(4) Concentration: 30 mg/mL

Applicable fields of various magnetic beads

1. Applicable fields of carboxyl magnetic beads

It can be covalently coupled with biological ligands such as peptides, proteins, antibodies, oligonucleotides, etc. under the action of special chemical reagents (such as EDC), and can be used in the following fields: affinity purification, chemiluminescence, cell sorting, biology Sensors, immunoassays, molecular diagnostics, etc.

2. Applicable fields of carboxyl magnetic beads (low non-specificity)

With low non-specific adsorption, it can be covalently coupled with peptides, proteins, antibodies, oligonucleotides and other biological ligands under the action of special chemical reagents (such as EDC), especially suitable for protein/cell sorting and immune monitoring , Biosensing, high-sensitivity analysis, etc.

3. Applicable fields of amino magnetic beads

It can be covalently coupled with biological ligands such as peptides, proteins, oligonucleotides, drug molecules, glycoproteins, etc. under the action of special chemical reagents (such as glutaraldehyde), and can be used as a good basic material for coating. An important carrier tool in medical and molecular biology research.

4. Applicable fields of mycostreptavidin magnetic beads

It can be efficiently coupled with biotinylated peptides, proteins, antibodies, oligonucleotides and other biological ligands, and is used in the following fields: chemiluminescence, cell extraction, cell classification, high-sensitivity analysis, immunoassay, biotin-labeled PCR extraction , Biosensing, gene expression analysis, etc.

5. Applicable fields of protein A magnetic beads

It is widely used in small systems, high-throughput IgG purification and labeling, immunoprecipitation, ChIP and protein separation. This technology is fast and gentle, and has very little physical pressure on the target protein. It is especially suitable for separating and concentrating unstable and easily decomposable components.

6. Applicable fields of protein G magnetic beads

It is widely used in small systems, high-throughput IgG purification and labeling, immunoprecipitation, ChIP and protein separation. This technology is fast and gentle, and has very little physical pressure on the target protein. It is especially suitable for separating and concentrating unstable and easily decomposable components.

7. Applicable fields of protein A/G magnetic beads

It is widely used in small systems, high-throughput IgG purification and labeling, immunoprecipitation, ChIP and protein separation. This technology is fast and gentle, and has very little physical pressure on the target protein. It is especially suitable for separating and concentrating unstable and easily decomposable components. Compared with SPA magnetic beads and SPG magnetic beads, SPA/G magnetic beads are suitable for more types of IgG.

8. Applicable fields of nucleic acid extraction silicon hydroxy magnetic beads

It is suitable for nucleic acid extraction and purification of plants, animals, whole blood, serum free, viruses, forensic samples, plasmids, PCR products, etc. It can be used with automatic nucleic acid extractors for high-throughput and automated operations.

The basic performance and applicable fields of various magnetic beads are described above. It can be seen that there are various types of biomagnetic beads, the basic performance is different, and the field of application is also different. Aisen Biotechnology produces a variety of types of magnetic beads with excellent performance and a wide range of applications. Customers in need are welcome to call for consultation.

Features of Nucleic Acid Extraction System and Precautions for Use

The nucleic acid extraction system is a biomedical system designed for automatic magnetic bead method nucleic acid extraction. You only need to add the sample to be extracted to the matching kit, put the kit into the extraction system, run the edited program that comes with the system, and complete a round of sample nucleic acid extraction in 15 to 30 minutes. The use of magnetic bead method nucleic acid extraction system is generally divided into two types: suction method and magnetic rod method.

ONE. The characteristics of the magnetic bead method of nucleic acid extraction system

1.Able to realize automation and high-throughput operation.
2. The operation is simple and fast.
3. Safety and environmental protection.
4. High purity and high yield.
5. No pollution and stable results.
6. Low cost, convenient for wide application.

HERO 32

TWO. Use method of magnetic bead method nucleic acid extraction system

1. Suction method

Also called pipetting method, nucleic acid extraction is achieved by immobilizing magnetic beads and transferring liquid. Generally, the transfer is achieved by controlling the mechanical arm through the operating system. The extraction process is as follows:

① Lysis: Add the lysis solution to the sample, realize the mixing and full reaction of the reaction solution through mechanical movement and heating, cell lysis, and release of nucleic acid.

②Adsorption: Add magnetic beads to the sample lysis solution and mix them thoroughly. The magnetic beads have a strong affinity for nucleic acids under high salt and low pH values ​​to adsorb nucleic acids. Under the action of an external magnetic field, the magnetic beads are separated from the solution. Use the tip to remove the liquid and discard it to the waste tank, and discard the tip.

③Washing: Remove the external magnetic field, replace with a new tip, add washing buffer solution, mix thoroughly to remove impurities, and remove the liquid under the action of the external magnetic field.

④Elution: Remove the external magnetic field, replace with a new tip, add elution buffer, mix thoroughly, and the bound nucleic acid is separated from the magnetic beads to obtain purified nucleic acid.

2. Magnetic rod method

The magnetic rod method realizes the separation of nucleic acids by fixing the liquid and transferring the magnetic beads. The principle and process are the same as the suction method, but the difference is the method of separating the magnetic beads and the liquid. The magnetic rod method is to separate the magnetic beads from the waste liquid through the adsorption of the magnetic beads on the magnetic rod, and put them into the next liquid to realize the extraction of nucleic acid.

THREE. Precautions for the use of magnetic bead method nucleic acid extraction system

1. The installation environment of the system: normal atmospheric pressure (altitude should be lower than 3000m), temperature 20-35℃, typical use temperature 25℃, relative humidity 10%-80%, unobstructed air flow is 35℃ or below.
2. Avoid placing the system close to a heat source, such as an electric heater; at the same time, to prevent short circuits of electronic components, avoid splashing water or other liquids into it.
3. The air inlet and exhaust vent are located on the back of the system, while avoiding dust or fibers from gathering at the air inlet and keeping the air duct unobstructed.
4. The nucleic acid extraction system is at least 10cm away from other vertical surfaces,
5. Grounding of the system device: In order to avoid electric shock accidents, the input power cord of the system device must be grounded.
6. Keep away from live circuits: Operators are not allowed to disassemble the system without authorization. Replacement of components or internal adjustments must be completed by qualified professional maintenance personnel. Do not replace components when the power is turned on.

At present, the magnetic bead method nucleic acid extraction system is widely used in various fields such as environmental microbial testing, food safety testing, blood transfusion safety, forensic medicine identification, disease control centers, clinical disease diagnosis, biological research, and animal husbandry.

Advantages and Principles of Magnetic Bead Method for Nucleic Acid Extraction

Since the birth of Watson and Crick’s DNA double helix model, biology has entered a new era. In the biological world, DNA is required, and the central rule is required. The extraction of DNA has become the field of biomedicine and even agriculture, forestry, animal husbandry and fishery. The foundation of scientific research in all disciplines, with the rapid development of genetic diagnosis, genetically modified food testing, personalized medicine, etc., the current nucleic acid extraction technology is no longer able to meet the needs of today’s biotechnology, and there is an urgent need for a high-throughput and automated nucleic acid extraction method . In this context, the magnetic bead method for nucleic acid extraction came into being. Next, the editor of Aisen will share with you the advantages and principles of magnetic bead method for nucleic acid extraction.

The advantages of magnetic bead method for nucleic acid extraction

1. It can realize automation and mass operation, eliminating the need for complicated manual extraction procedures;

2. The operation is simple, the time is short, and the labor cost is reduced;

3. It does not use toxic reagents such as benzene and chloroform in the traditional method, which is safe and non-toxic, in line with modern environmental protection concepts, and reduces the harm of phenols, chloroform and other organic reagents to operators;

4. The specific binding with nucleic acid makes the extracted nucleic acid with high purity and high concentration;

5. It is suitable for clinical molecular diagnosis, which greatly meets the requirements of the market for nucleic acid extraction technology.

ASCEND HERO 32

The principle of magnetic bead method of nucleic acid extraction

The binding of nucleic acid to magnetic beads mainly relies on electrostatic, hydrophobic and hydrogen bonding. The DNA/RNA in the cell or tissue is released under the action of the lysis solution. At this time, the surface-modified superparamagnetic silica nanomagnetic beads “specifically bind” with nucleic acid to form a “nucleic acid-magnetic bead complex”. Then under the action of an external magnetic field, the complex is separated. After the eluate is washed to remove the non-specifically adsorbed magazines, desalted and purified, the nucleic acid substance to be extracted is obtained.

The relevant introduction of the advantages and principles of magnetic bead nucleic acid extraction is the above. The magnetic bead nucleic acid extraction technology has many application advantages, and its future development prospects are good, and it is worthy of popularization and application.

What are the factors that affect the extraction of magnetic beads?

Magnetic beads play an important role in nucleic acid extraction. The specific process is to first lyse the cells, then combine nucleic acids with magnetic beads through the binding solution, and use washing solution to wash away residual protein and salt ions, and then combine nucleic acids and magnetic beads. Separate. Seeing that the process is very simple, there are actually many factors that influence it. Next, I will tell you what are the factors that affect the extraction of magnetic beads.

1. The binding capacity of magnetic beads and nucleic acid

The top priority of the magnetic bead method for nucleic acid extraction is the adsorption capacity of the magnetic beads and nucleic acid, which directly affects the yield of nucleic acid extraction. In order to improve the performance of magnetic beads for binding nucleic acids, various magnetic bead manufacturers have tried various methods, but there are no more than two types of magnetic beads on the market: ionic bond magnetic beads and covalent bond magnetic beads. Ion-bonded magnetic beads are represented by silica gel-based magnetic beads. This type of magnetic beads is more and more due to their manufacturers, and there are endless kits on the market, but the principles are similar. The other type of covalently bonded magnetic beads is the cellulose membrane magnetic beads. Both types of magnetic beads cover most of the fields of nucleic acid extraction: medical, scientific research, blood station, disease control, forensic and other fields. The products also include whole blood DNA/RNA extraction, plants, animal tissues, saliva, cells, bacteria, viruses and other samples.

2. The magnetic force on the surface of the magnetic beads

The magnetic force on the surface of the magnetic beads is also one of the factors affecting nucleic acid extraction. No matter how strong the magnetic beads are for nucleic acid binding, if the magnet has a limited adsorption capacity, many magnetic beads will be lost during operation, and nucleic acid will be lost indirectly. Because of the special nature of the cellulose film, its ability to shield magnetic properties is poor, so the magnetic force on the surface of the cellulose film magnetic beads is stronger, and it is easier to adsorb tightly near the magnetic stand.

Magnetic-Beads-others

3. Equipment operation mode

At present, there are two main types of automation equipment: magnetic rod method and suction method. Suction method, also called pipetting method, is to achieve nucleic acid extraction by fixing magnetic beads and transferring liquid. Generally, the operating system controls the robotic arm to achieve the transfer, and the nucleic acid extraction is achieved through lysis-adsorption-washing-elution; magnetic rod The method is to realize the separation of nucleic acid by fixing the liquid and transferring the magnetic beads. The principle and process are the same as the suction method, but the difference is the method of separating the magnetic beads and the liquid. The magnetic rod method is to separate the magnetic beads from the waste liquid through the adsorption of the magnetic beads on the magnetic rod, and put them into the next liquid to realize the extraction of nucleic acid.

The main factors that affect the extraction of magnetic beads are the above three types. You can refer to them when choosing magnetic beads to ensure that the magnetic beads are used well. The magnetic beads produced by Aisen Biotechnology are of excellent quality and outstanding performance. They are very helpful in nucleic acid extraction. They can bind the target substance in a short time and avoid accidental injury to the human body. Customers in need are welcome to call for consultation.

What are the types of nucleic acid extractors

Nucleic Acid Extraction System (Nucleic Acid Extraction System) is an instrument that uses matching nucleic acid extraction reagents to automatically complete sample nucleic acid extraction. It is widely used in various fields such as the Center for Disease Control, clinical disease diagnosis, blood transfusion safety, forensic identification, environmental microbiological testing, food safety testing, animal husbandry and molecular biology research.

1. Classification according to the size of the instrument model

①Automatic liquid workstation

The automatic liquid workstation is a very powerful device, which automatically completes liquid dispensing and aspiration, and can even realize full automation of specimen extraction, amplification, and detection by integrating functions such as amplification and detection. Nucleic acid extraction is only one application of its function, and it is not suitable for routine laboratory extraction of nucleic acid. It is generally applied to the experimental needs of a single type of specimen and a very large amount of specimens (at least 96, generally several hundred) at a time. The platform establishment and operation of automatic workstations require relatively large funds.

②Small automatic nucleic acid extractor

The small-scale automated instrument achieves the purpose of automatically extracting nucleic acid through the particularity of the operating structure, and can be used in any laboratory.

TianLong GeneRotex 96

2. Classification according to the extraction principle

①Apparatus using spin column method

The centrifugal column method nucleic acid extractor mainly uses a combination of a centrifuge and an automatic pipetting device. The throughput is generally 1-12 samples. The operation time is similar to that of manual extraction. It does not improve the actual work efficiency and is expensive. Different models The consumables of the instrument are not universal, and are only suitable for large-scale laboratories with sufficient funds.

②Apparatus using magnetic bead method

Using magnetic beads as a carrier, using the principle of magnetic beads adsorbing nucleic acids under high salt and low pH values, and separating them from nucleic acids under low salt and high pH values, the entire nucleic acid extraction and purification process is realized by moving the magnetic beads or transferring the liquid. Due to its unique principle, it can be designed into a variety of fluxes. It can be extracted from a single tube or 8-96 samples, and its operation is simple and fast. It only takes 30-45min to extract 96 samples, which greatly improves The efficiency of the experiment and the low cost allow it to be used in different laboratories. It is currently the mainstream instrument on the market.

The above are the common types of nucleic acid extractors introduced. Aisen Biotech Co., Ltd. introduced the HERO96 nucleic acid extractor to the market. It is a biomedical instrument specially used for fully automatic magnetic bead method for nucleic acid extraction. Simply add the sample to be extracted to the matching kit, put the kit into HERO96, run the program that comes with the instrument, and complete a round of extraction of 96 nucleic acid samples in 15-40 minutes. The unique cryopreservation function of HERO96 can ensure the quality of the extracted product when you cannot process the extracted nucleic acid in time.

How to do nucleic acid testing for frozen food

We know that the rapid detection and sampling of human neocorona nucleic acid is mainly through nasopharyngeal swabs or oropharyngeal swabs. So how to do rapid detection of new crown nucleic acid for frozen food? In fact, the rapid detection of COVID-19 for food is similar to the rapid detection of human COVID-19. Next, let’s take a look at popular science for you:

1. Collection of seafood, fish and water samples

First open the gills of the fish sample, take a sampling swab, wipe 5-10 times on the gills, then put the sampling swab head into the collection tube containing the preservation solution, break the handle, and then seal it for inspection. ; Store the ice water sample of the fish, use a disposable plastic straw to suck 3-5ml into a 5ml preservation tube, and then seal it for inspection.

2. Frozen food for nucleic acid testing

For the rapid detection of COVID-19 on frozen foods, priority should be given to the collection of tissues with obvious diseased organs; secondly, aquatic products should be given priority to samples with internal organs and surrounding tissues; again, the same animal should be collected in the order of the sample types listed in the above table. The swab must be applied at the same time. No more than 3 samples can be collected from the same animal; finally, two samples are collected for each sample, one for testing and one for backup.

Animal-Genomic-DNA2

In addition to applying a swab on the surface of the food, the tissue also needs to be homogenized (homogenization is also called homogenization, which is a process of micronizing and homogenizing the dispersion in the suspension (or emulsion) system. This treatment simultaneously reduces the size of the dispersion and improves the uniformity of the dispersion), and then performs the normal rapid detection of new coronavirus nucleic acid, that is, reagent preparation, nucleic acid extraction, amplification detection, and issuance of reports.

3. Sampling of the surface of the object

Mainly cutting boards, knives, vegetables, meat, etc. First take a sampling swab, after soaking it in the preservation solution (if the surface of the object is wet, you can directly sample), wipe it horizontally and vertically on the surface of the object 5 times, and then put the sampling swab head into the collection tube containing the preservation solution. The handle is broken off, and then sealed and sent for inspection.

At present, most of the sporadic epidemics in many places are caused by cold chain foods, so the rapid detection of new crown nucleic acid in cold chain foods should also be attached great importance. It is necessary to strictly follow the sampling specifications and carefully sample the food and environment that may be contaminated. The rapid detection and sampling of new crown nucleic acids are mainly carried out for various types of frozen food, food packaging, related supplies and related staff, so as to achieve a comprehensive investigation, Leave no dead ends.

Common classification and separation principle of magnetic beads

With the continuous development and improvement of extraction technology, magnetic bead extraction technology continues to rise in China. As the core material for extraction, magnetic beads are constantly being known. Magnetic beads are formed by covering a core of ferroferric oxide with a certain tissue, which can be adsorbed by magnets and at the same time have magical beads that can adsorb (bind) nucleic acids through surface coatings. The reason why he is said to be magical is that he is very useful! It can realize the automation and high throughput of nucleic acid extraction. So who are his family members? Next, I will share with you the common classification and separation principle of magnetic beads.

The main classification of magnetic beads

1. Silica gel magnetic beads

This is a type of nucleic acid-binding magnetic beads that appeared very early on the market, and it is also one of the widely used magnetic beads on the market. The reaction principle is that under the condition of high salt ion, nucleic acid and silica gel plasma membrane bind nucleic acid by positive and negative electric adsorption force, and then the nucleic acid is eluted and separated in the environment of low salt ion to achieve the purpose of nucleic acid extraction.

2. Amino magnetic beads

Amino magnetic beads are modified with amino groups on the basis of silica gel plasma membrane magnetic beads. By changing the pH of the solution, the combination and separation of nucleic acids and magnetic beads can be achieved. Of course, the pH value of this method is controlled. To meet the requirements, otherwise it will affect the nucleic acid binding and elution effect.

3. Hydroxyl magnetic beads

Hydroxyl magnetic beads are based on silica gel plasma membrane magnetic beads, with hydroxyl modification groups added, and the principle is similar to amino magnetic beads.

4. Aldehyde-based magnetic beads

After the silica gel plasma membrane magnetic beads are modified with the aldehyde group, the aldehyde group is combined with a specific primer to catch a specific nucleic acid. However, the cost of such magnetic beads is relatively high. The principle of the other aldehyde-based magnetic beads (no specific primer modification) is similar to the principle of the combination of amino and hydroxyl groups.

5. Cellulose coated magnetic beads

Cellulose-coated magnetic beads are another type of magnetic beads currently on the market. They are different from the silica-based plasma membrane series of magnetic beads. The cellulose membrane magnetic beads have a rougher surface and a larger relative surface area. The principle is to use the hydrophilicity of the cellulose membrane to combine with hydrophilic nucleic acids in a hydrophobic environment. This hydrophilic and hydrophobic binding force (covalent bond) is stronger than the positive and negative electric binding force (ionic bond).

Nucleic Acid Extraction Carboxyl Magnetic Beads

The principle of magnetic bead separation of nucleic acids

The surface of nano-scale magnetic beads is modified with specific active functional groups that can adsorb nucleic acids. By using different lysis solutions, binding solutions, and washing solutions, they can specifically bind to the target nucleic acid under specific conditions, while using magnetic beads Its own magnetism can easily realize directional movement and enrichment under the action of an external magnetic field, so as to achieve the purpose of separating nucleic acid and impurities, and then realize the separation and purification of target substances to obtain purified nucleic acid.

Introduction of Magnetic Bead Method for Nucleic Acid Extraction Kit

There are many types of nucleic acid extraction kits. Today, we will mainly introduce the principle, use method and specific steps of the magnetic bead method nucleic acid extraction kit.

  1. What is nucleic acid

Nucleic acids are widely present in all animals, plant cells, and microorganisms. Nucleic acids in organisms often combine with proteins to form nucleoproteins.

According to different chemical composition, nucleic acid can be divided into ribonucleic acid, referred to as RNA and deoxyribonucleic acid, referred to as DNA. DNA is the main material basis for storing, copying and transmitting genetic information. RNA plays an important role in the process of protein synthesis, among which transfer ribonucleic acid, tRNA for short. Plays the role of carrying and transferring activated amino acids; messenger ribonucleic acid, referred to as mRNA, is the template for protein synthesis. Ribosomal ribonucleic acid, rRNA for short, is the main place where cells synthesize proteins.

  1. What is the magnetic bead method nucleic acid extraction kit

The magnetic bead method nucleic acid extraction kit uses a unique separation of magnetic beads and a buffer system to separate and purify high-quality genomic DNA from the sample. Special coated magnetic beads have a strong affinity for the target DNA under certain conditions. , And when the conditions change, the magnetic beads release the adsorbed DNA, which can achieve the purpose of rapid separation and purification of DNA. The whole process does not involve toxic reagents, it is safe, convenient, and the extracted DNA is of high purity. The genomic DNA (OD260-0D320/(0D280-0D320) purified by this kit is between 1.7 and 2.0, which can be applied to various downstream molecular biology experiments.

The magnetic bead method nucleic acid extraction kit uses a unique separation of magnetic beads and a buffer system to separate and purify high-quality genomic DNA from the sample. Special coated magnetic beads have a strong affinity for the target DNA under certain conditions. , And when the conditions change, the magnetic beads release the adsorbed DNA, which can achieve the purpose of rapid separation and purification of DNA. The whole process does not involve toxic reagents, it is safe, convenient, and the extracted DNA is of high purity. The genomic DNA (OD260-0D320/(0D280-0D320) purified by this kit is between 1.7 and 2.0, which can be applied to various downstream molecular biology experiments.

Accounting extraction kit: DNA extraction kit, RNA extraction kit

Composition: Lysis solution, binding solution, washing solution, eluent, biomagnetic beads, instructions

  1. Use steps of magnetic bead method nucleic acid extraction kit:

  1. Add Buffer C1, humic late adsorbent C2 and glass beads to the soil sample and vortex.
  2. Add BufferC3 to lyse the cells
  3. Add Buffer C4 to deform and precipitate protein
  4. Gaoxin removes impurities such as large humic acid
  5. Add BufferC 5. Ethanol to adjust the binding conditions
  6. Transfer to a separation column and centrifuge to adsorb DNA
  7. Add washing liquid to wash and remove impurities such as salt
  8. Centrifuge for 1min to spin dry the base shield
  9. Add TE and centrifuge for 1 min to elute DNA
  10. High-quality DNA

The above is the relevant introduction of the magnetic bead method nucleic acid extraction kit, including the classification, composition, and specific use method steps of the nucleic acid extraction kit.