[Effect of activators for activated partial thromboplastin time test on its results in the tube and automated test versions].

Effects of activators used in combination with partial thromboplastin (PT), manufactured by the Kirov Institute of Hematology and Blood Transfusion, on the results of the activated partial thromboplastin time (APTT) test and its sensitivity to heparin were studied. Kaolin manufactured in Russia and by Aldrich firm and silica from Sigma were used. The method was reproduced in tubes and on Organon Teknika photooptic coagulometers: semiautomatic Coag-A-Mate XM and automated Coag-A-Mate RA-4. The concentration and optical density of the activator affected the results of APTT test, which prompts the use of kits calibrated for the PT/activator combination but not separate reagents. Combination of PT manufactured by the Kirov Institute and suspension of Russian kaolin ensured high sensitivity of the method to heparin content in the plasma and good reproducibility of the method both in tubes and on Organon Teknika coagulometers: coefficient of variation of APTT in all variants of the tube test were no higher than 10% and in the automated variant 2.6-6.2%.