Hematology tests of blood anticoagulated with magnesium sulphate.

Venous blood treated with magnesium sulphate (MgSO4) at blood collection was used for hematology tests. Complete blood counts and automated leukocyte differentials were obtained using a hematology analyzer, and the results obtained for blood treated with MgSO4 were similar to those for blood treated with dipotassium ethylenediaminetetraacetic acid (EDTA K2). Coagulation tests such as activated partial thromboplastin time, platelet factor 3 availability and prothrombin time were dose-dependently affected by the use of MgSO4. Thrombin time was prolonged by addition of MgSO4, and fibrin concentrations determined by coagulometry tended to decrease with addition of MgSO4, although fibrin concentrations determined by the weighing method were unaffected by MgSO4. MgSO, was thus found to potently inhibit blood coagulation and can be used as an anticoagulant for hematology tests.

Problems on national and locale external quality assurance schema (NEQAS and LEQAS); based on Japanese experience.

The quality and stability of surveillance materials is a critical issue to perform good external quality assessment schema. In the case of nationwide surveillance, more stable materials are required than those in the case of locale external quality control schema. For locale surveillance, fresh blood, plasma or serum materials are prepared for hematology and chemistry tests. On the other hand, dried materials are used for the chemistry test and semi-fixed blood is used for hematology tests in the national surveillance. However to evaluate automated white cell differential in hematology, there has been no good materials. We therefore prepared a mixture of EDTA and ACD solution for our locale surveillance. It gave us excellent results on the differential when we used it within 3 days after blood collection.