This product is designed for use as a positive control for anti-epitope tag antibodies. This E.coli lysate contains a recombinant protein comprised of the following commonly used epitope tags: MBP--T7--HSV--cMyc--VSV--Glu-Glu--V5--E-tag--Flag--S tag--HA--6XHis. A 58 kDa recombinant protein is a visualized after SDS-polyacrylamide gel electrophoresis and western blotting using an antibody recognizing any of the expressed epitope tags listed above. The E.coli lysate was prepared by lysing cells in loading buffer, heating to 95° C for 10' followed by centrifugation at 13,000 g for 15'. Thaw the lysate to room temperature. Gently invert vial several times to ensure that the solution is homogeneous and that any precipitated material is re-dissolved. A loading volume of 0.25 to 2 µL is recommended for western blotting. The product is supplied in 1X loading buffer and is ready-to-use. 62.5 mM Tris HCl, 10% Glycerol, 2% SDS, 0.05% bromphenol blue, pH 6.8 + 1% Triton 100 + 2.5 mM EDTA+5mM Tris HCl+4% (v/v) β-Mercaptoethanol.