Disclosed is a procedure for conducting anti-thrombin III assays in which the conventional thrombin-anti-thrombin III treatment step is conducted at a pH of 7.9 to 8.5 maintained at the level by a buffer system comprising a buffering amount of N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid, N-2-hydroxyethylpiperazine-N'-3-propanesulfonic acid, N-tris-(hydroxymethyl)-methyl-2-amino-ethanesulfonic acid, N-tris-(hydroxymethyl)-methylglycine, or N,N-bis (2-hydroxymethyl)-glycine or a salt thereof. The compositions may also contain bacteriostatic agents.

A process for testing a blood sample as for coagulation, hematology, chemistries, enzymes, electrolytes and trace metals which involves the addition of a particular anticoagulant. The anticoagulant is a calcium chelating agent having a Log K' of from about 3.4 to 4.2.

A rapid and reliable method is disclosed for determining the presence or absence of endotoxins in solution, including biological liquids such as transudates and exudates. The method comprises a procedure based upon the alteration of a modified coagulation test system by endotoxins produced by gram-negative microorganisms. The method is particularly useful as reliable aid in the early diagnosis and treatment of infections caused by gram-negative microorganisms and to alert the diagnostician to the possibility of septic shock in an infected host.

Coagulation control compositions suitable for use in connection with PT and/or APTT assays are disclosed along with their methods of preparation and methods of use. Preferred coagulation controls comprise plasma and an anticoagulant having activity for enhancing the activity of antithrombin III (ATIII) or of heparin co-factor II (HCII) against thrombin or against a clotting factor selected from the group consisting of factors IXa, Xa and XIa. The anticoagulant is preferably a glycosaminoglycan such as heparin, a heparin derivative or a heparin analog. The anticoagulant is preferably combined with (1) an abnormal plasma (e.g. activated plasma or factor-deficient plasma) and/or (2) a primate plasma (e.g. human plasma), and a non-primate mammalian plasma (e.g. bovine plasma). In the latter case, the non-primate mammalian plasma is preferably present in the coagulation control composition in an amount of not more than about 12% by volume, relative to total volume.

A method for preparing a coagulation control sample which is stable in the absence of buffer and which has a clotting time within the range of normal human clotting times for reproducibly monitoring coagulation capability in a human patient comprising (a) collecting blood from a mammalian animal, (b) removing red blood cells from the blood to produce mammalian plasma, and (c) adding to the plasma an amount of at least one non-primate mammalian plasma that has been adsorbed with a coagulation factors II, VII, IX and X adsorbent prior to addition of the plasma to the mammalian plasma.