Q：What are the advantages of your magnetic microspheres?
A：First of all, our magnetic microspheres are spherical, and there are no gaps in the surface that can lead to waste of antibodies, oligonucleotides, or other ligands during coupling. Secondly, the surface of the microsphere is rough. The rough surface of the microsphere can effectively increase the specific surface area, so that more ligands can be bound to the surface of the microsphere. In addition, the particle size of our microspheres is the same and the distribution is uniform. In magnetic separation, the microspheres have fast magnetic response and good redispersion. At the same time, the microspheres have the characteristics of low density and can stay in the solution for a long time to make full reaction.
Q：When we used 0.3-0.5um color-dyed microspheres for chromatography on the top of the immunochromatographic strip, however, only the mixed mobile phase of organic and water can be used for chromatography at present, do we need to try other microspheres with different particle sizes?
A：The reasons for the poor fluidity of the microspheres are as follows: 1. The particle size of the microspheres may be too large to effectively pass through the pore size of the chromatographic strip; 2. The microspheres are aggregated in the buffer solution and cannot penetrate the filtration membrane; 3. The microspheres are bonded to the surface of the membrane by hydrophobic bonds; As organic solvents are used, colored dyes may be seen flowing on the strip. We advise to use the microspheres with smaller particle size, chromatography paper with larger pore size and the addition of surfactant to make the microspheres more dispersive. Or a protein or surfactant can be used to seal the surface of the membrane to reduce its adhesion to the immune microspheres.
Q：Does it need to be washed before the antibody coupling of the microspheres, and will the microspheres precipitate after washing?
A：The microsphere preservation solution contains trace amounts of surfactants and stabilizers, which may have a certain impact on the downstream antibody coupling. PBS or any other buffer solution that can be used for coupling reaction can be commonly used for washing buffer. If agglomeration and precipitation occur in the washing process, the microspheres can be resuspend by means of eddy oscillation or ultrasound, etc. If the microspheres are still aggregated, extremely small amounts of surfactant should be added to the microspheres after washing to maintain the suspension state of the microspheres.