Nanomagnetic beads refer to small magnetic particles whose size is suitable to be measured by nanometers, generally 1-100 nanometers. This kind of magnetic beads has a very special magnetic property called superparamagnetism, that is, it has a strong magnetic field in an external magnetic field. Responsiveness, and after the magnetic field is removed, the magnetic properties of the magnetic particles disappear immediately, that is, there is no remanence, and they are uniformly dispersed in the solution again. Traditional DNA separation technology includes precipitation, centrifugation and other processes. These purification methods have complicated steps, time-consuming, low yield, and contact with toxic reagents. It is difficult to realize automatic operation; however, the use of magnetic carrier microsphere separation technology can overcome it well. These shortcomings enable rapid and efficient sample preparation. Therefore, nanomagnetic bead technology is an important direction for the development of DNA purification methods in the future.
What are nano magnetic beads
The so-called nano magnetic beads refer to small magnetic particles whose size is suitable to be measured by nanometers, generally referring to 1-100 nanometers. This kind of magnetic beads has a very special magnetic property called superparamagnetism, that is, it has a strong magnetic field in an external magnetic field. Magnetic responsiveness, and after the magnetic field is removed, the magnetic properties of the magnetic particles disappear immediately, that is, there is no remanence, and they are uniformly dispersed in the solution again.
Scientists favor this feature, which can be used to adsorb a certain component in the liquid, and then magnetically separate the magnetic beads to achieve the purpose of separating the components. Of course, in order to be able to adsorb the desired substance, specific groups must be wrapped on the outside of the particles, such as amino, hydroxyl, carboxyl, sulfhydryl and other functional groups. These groups are specifically combined with the target molecule, and then collected by magnetic force. Magnetic beads can separate the required substances.
The magnetic beads themselves are mostly inorganic materials, the most common material is ferroferric oxide, and the outer covering is basically organic material. According to the position relationship between the magnetic bead itself and the coating material, there are four types of magnetic bead structures, namely, core-shell type, mosaic type, core-shell type, and core-shell type.
Among them, the first core-shell type has been studied and used the most. Its magnetic material is used as the core, and the polymer material is used as a shell to wrap the outside of the magnetic particles. The inorganic magnetic material at the core endows the entire particle with superparamagnetism. Separation, the high-molecular substance in the shell gives the entire particle high-efficiency adsorption, that is, specificity. In a fully mixed and uniform liquid environment, the polymer shell is combined with the target substance through its functional group, and the movement and collection of the entire particle is controlled by an external magnetic field, and finally the goal of separation of the target substance is achieved.
The use of magnetic beads for DNA extraction is one of the areas where their biological value is maximized. The main types of microspheres used include silanol magnetic beads and oligo magnetic beads. Magnetic beads with surface groups can specifically and reversibly bind to nucleic acids released in the test sample. At the same time, the magnetic response capability of the magnetic beads is used to carry out directional movement and enrichment under the action of an external magnetic field, so as to realize the separation and purification of nucleic acids. The main advantages of the magnetic bead method for nucleic acid extraction include simple and automated operation, large-scale operation, and short time.