Bz-IEGR-pNA is a colorimetric substrate for Factor Xa.1 Factor Xa preferentially binds to and cleaves the Ile-Glu-Gly-Arg (IEGR) peptide sequence to release p-nitroanilide (pNA), which can be quantified by colorimetric detection at 405 nm as a measure of Factor Xa activity.References1. Aruell, L., Friberger, P., Karlsson, G., et al. A new sensitive and highly specific chromogenic peptide substrate for factor Xa. Thromb. Res. 11(5), 595-609 (1977). Bz-IEGR-pNA is a colorimetric substrate for Factor Xa.1 Factor Xa preferentially binds to and cleaves the Ile-Glu-Gly-Arg (IEGR) peptide sequence to release p-nitroanilide (pNA), which can be quantified by colorimetric detection at 405 nm as a measure of Factor Xa activity. References1. Aruell, L., Friberger, P., Karlsson, G., et al. A new sensitive and highly specific chromogenic peptide substrate for factor Xa. Thromb. Res. 11(5), 595-609 (1977).