Establishment of automated processing for blood coagulation test using IDS-CLAS3600

Abstract

Automated transportation systems and processors are very useful for handling large amounts of blood samples. Processors are commonly used for serum processing, but rarely for citrated plasma processing. In this study, we evaluated the performance of the IDS-CLAS3600 processor and established the optimal conditions for citrated plasma separation. Initially, we aimed to optimize the centrifugation conditions in accordance with the Clinical and Laboratory Standards Institute (CLSI) guideline. We found that 2,600 g for 5 min showed the best performance with less platelet contamination and a shorter processing time. CLAS3600 consists of four main units with the following functions: detecting blood cell layer, cap opening, dispensing and exporting. We evaluated the performance of blood cell layer detection, and we found no significant differences between CLAS3600 measurement and caliper measurement. We further investigated the aspiration point (dummy length) and aspiration speed. Residual platelet number in dispensed plasma was not affected by both the aspiration point and speed; however, a larger dummy length resulted in a lower yield than expected for dispensed plasma. On the basis of these results, we determined the optimal dispensing conditions to be as follows: dummy length, 6 mm; aspiration speed, 90% of that under serum conditions. These conditions were validated using plasma samples with thrombocytosis or polyemia, which were prepared artificially. As a result, we found that contaminating platelets were less than 10 × 10⁹/L. We have been using CLAS3600 for 5 years as the automated processor for the coagulation test, and there has been no error in the aspiration of the blood cell layer. Our established system has contributed to saving human effort and time, and resulted in an effective workstyle.