Regeneration of Streptavidin-coated Paramagnetic Beads for Multiple uses in Inter-membrane Lipid Transfer Assays

Abstract

The specificity and the strong binding capacity of the biotin-streptavidin complex make the system one of the most widely used affinity pairs in molecular, immunological and cellular (in-vitro) assays. Previously reported regeneration process of the active Streptavidin solid support in DNA sequencing using water at temperatures above 70 oC, without denaturing the Streptavidin tetramer is shown in this study to be ineffective for a previously used Streptavidin-coated magnetic beads used in lipid transfer assay. Regeneration of the used beads in chloroform inactivated the beads while the use of 10 M NaOH destroyed the solid support of the bead. However, regenerating the paramagnetic beads used in lipid transfer assay with 25% aqueous ammonia only and with 25% aqueous ammonia in methanol (9:1) at 25 oC was very effective, with their reuse efficiency being 90% after recovery. This represents ca. 50 – 67 % research cost savings, especially in this era of economic depression.