UniFilter-96 GF/C PEI Coated Plates

These plates are designed with a built-in glass fiber filter for receptor binding assays or cell harvesting using a manifold. It is available in two different glass membranes: GF/B is a glassfiber membrane approximately 680 µm thick and the GF/C version is approximately 260 µm thick.

Polyethyleneimine (PEI) is a cationic polymer that can neutralize the negative charge of glass fiber filters (GF/C, GF/B). Treating GF/C and GF/B filter plates with polyethylenimine (PEI) is often used to minimize non-specific binding, particularly in ligand-binding assays. For some applications involving negatively-charged ligands (such as GTP binding assays), PEI coating could cause problems by creating a positively-charged surface that actually promotes non-specific binding to the filter, due to the negative charge on the ligand.