SoftLink™ resin is a rigid, methacrylate polymeric gel filtration matrix, functionalised with covalently bound, monomeric avidin. Used for the isolation and purification of biotinylated molecules.

• Specific capture of biotinylated proteins with reversible binding under mild elution conditions
• Binding ability retained under a wide range of pHs, and low or high ionic strength solutions
• Regenerates at least 10 times without loss of binding capacity

Monomeric avidin binds biotin with a K_d value of 10⁻⁷ M, allowing reversible binding of bound biotinylated proteins under mild elution conditions. Native, or tetrameric, avidin binds biotin with a very strong affinity (K_d=10⁻¹⁵ M), which in turn requires strong denaturing conditions for eluting bound material.

SoftLink resin binds 20 to 40 nmol of biotinylated protein per milliliter of resin. Bound biotinylated molecules can be eluted under mild nondenaturing conditions (5 mM biotin).

Applications: Purification of biotinylated antibodies and other proteins, purification of in vivo biotinylated fusion proteins from PinPoint™ vectors and reversible binding of biotinylated proteins under mild non denaturing conditions.