The activated partial thromboplastin time (APTT) cross-mixing test is useful for screening coagulation factor deficiencies and inhibitors including lupus anticoagulants. Because the mixing test procedure is complicated owing to the manual preparation of specimens, the test is performed in only a few laboratories. Here, we used the fully automatic clinical laboratory system STACIA for mixing test, which is a general-purpose machine (LSI Medience, Inc.) and we deviced a more easily mixing test method as the SATCIA method. In addition, we compared the STACIA method with the TOP method which is the semiautomatic mixing test method using ACL-TOP500 (Instrumentation Laboratory, Inc.). The TOP method requires the manual preparation of a diluted sample for warming, but in the STACIA method, this is performed automatically. So the STACIA method is simple and easy, because dispensing work is not necessary. Also, we calculated the sensitivity for detecting inhibitors by the waveform pattern method, ICA, and CMT index, respectively for evaluating the STACIA method. The sensitivity values observed in the waveform pattern method, ICA, and CMT index were 75.0%, 79.2%, and 91.7%, respectively. The CMT index was the most sensitivity is good. The STACIA method can be measured both of immediate test and incubated test with half the sample volume required in the TOP method. Also, this method leads to both labor saving and increased accuracy of the results. In addition, numerical values were obtained for the evaluation of the results by this method. We conclude that the mixing test using STACIA can be useful for detecting coagulation abnormalities such as factor deficiencies or inhibitors as part of routine duties.
