Size exclusion chromatography (SEC) uses gel filtration resins to separate molecules based on their size. The column is packed with a gel filtration resin, which consists of beads with pores of a specific size. As the sample passes through the column, molecules smaller than the pore size of the resin enter the pores and take longer to elute from the column, while larger molecules flow around the beads and are eluted more quickly.

SEC is commonly used in protein chemistry for buffer change, to remove small molecules such as salts, detergents, or unreacted reagents (dNTP, fluorescent dyes etc.) that might interfere with downstream applications, such as enzymatic assays or protein crystallization etc.

Size exclusion chromatography by centrifugation (SECC) uses centrifugation force in stead of gravity-flow, which is much faster.

Epoch Life Science supplies a number of spin column for SECC. Both empty and prepacked columns are available. If you don't see it please ask.