S-Trap™ sample processing technology is convenient spin columns or automatable 96-well plates that enable the use of SDS in proteomics sample preparation. SDS is a nearly universal protein solvent that dissolves even poorly-soluble molecules like membrane proteins which are often discarded as pellets. S-Trap™ sample processing begins with sample lysis and solubilization in 5% SDS. Proteins are further denatured by acidification to pH < 1 and subsequent exposure to a high concentration of methanol. This three-stage denaturation ensures complete destruction of undesired enzymatic activity such as proteases and phosphatases, and maximizes efficiency of downstream digestions. Reduction and alkylation can be performed in 5% SDS, precluding precipitation, or alternatively on-column after the denatured proteins are trapped.
Denatured, non-digested proteins are bound to the S-Trap via centrifugation, positive pressure or vacuum. Multiple weak-affinity interactions hold the undigested protein within the pores of the derivatized silica S-Trap. Captured proteins are presented with maximal surface area allowing them to be washed fully free of all contaminants in only minutes: detergents, PEG, glycerol, detergents, salts, Laemmli loading buffer, etc.
Upon addition of your choice of protease, physical confinement within the submicron pores of the trap forces substrate and protease interaction to yield rapid digestion. The trap does not have affinity for peptides, which elute after digestion.
S-Traps are available as spin columns, 96-well plates or full kits with premade buffers for convenience, minimal prep time and maximum reproducibility. 96-well plates are compatible with multiple automated platforms including the Tecan A200 positive pressure workstation and Agilent Bravo.