PT Liquid 2 _ PT Liqud 4 910818PT Liquid 2 _ PT Liqud 4 910818PTT Liquid is a rabbit brain cephalin for the determination of the Activated Partial Thromboplastin Time, a qualitative and quantitative screening test for the exploration of the intrinsic coagulation pathway (Factors XII, XI, X, IX, VIII, V, II, I). It is based on the recalcification of the plasma in the presence of a standardized activator (Ellagic Acid) with measurement of the time of formation of the clot.