Magnetic Silica Beads For Surface Chemistry

Amsbio (AMS Biotechnology) are an important supplier of magnetic silica beads (MagSi) who can provide beads customised for a number of different properties, including binding and surface properties, sizes, kinetics and optical characteristics.

The principle behind the use of magnetic silica beads for purifying proteins, and proteomic and genomic applications, is remarkably simple but provides for any number of elegant modifications. By coating the variously sized nanoparticles with ligands, or proteins like Streptavidin, with specific binding properties, positive or negative selection processes can be applied to both solutions and suspensions.

Both molecules and cells or cell compartments can be targeted as required. Tubes need only then be placed into welled ‘separators' equipped with strong permanent magnets for isolation to rapidly proceed - in many cases the full process takes less than 2 minutes. Columns are not required and the facility to encapsulate dyes, quantum dots and ferro fluids in the beads means that magnetic silica beads can readily be used in automatic procedures. 

Amsbio provide a comprehensive range of magnetic silica beads. Standard sizes are 600 nm, 1 μm and 1.2 μm. Decreasing the size of particle increases the surface area for adsorption/separation while causing some diminishing of the magnetic strength. Typical surface coats in addition to Streptavidin and Protein A and Protein G include silica, COOH. NH2 CHO C18-C4 and the tosyl functional group (CH3C6H4SO), Tosyl beads are recommended for the conjugation of small peptides via a stable amide bond.

MagSi magnetic silica beads have also been developed for DNA extraction to address two different needs. The first is for high throughput applications like whole blood isolations and food diagnostics and these beads have a dense iron core with a strong magnetic response. Whereas the priority for some complex, manual DNA procedures is DNA selectivity, low non-specific binding and great DNA capture. 

The technology is now really at the stage where beads can be tailored specifically to meet your research requirements and there seems to be every likelihood that the more and more applications are going to be forthcoming.

Date added: 2015-05-25 11:58:38