Quantitative buffy coat analysis of blood collected from dogs, cats, and horses.

Using quantitative buffy coat analysis (QBCA), rapid and accurate measurements can be made of the erythrocyte PCV, total WBC count, and platelet count, and the leukocyte population can be differentiated into total granulocytes (including quantitation of eosinophils), and lymphocytes and monocytes. The QBCA is performed by placing a blood sample (50 to 111 microliters) into a high-precision-bore microhematocrit tube that contains a freely moving, closely fitting, cylindrical plastic float. After centrifugation for 5 minutes, the buffy coat components separate by density. The plastic cylinder floats in the buffy coat, thereby expanding the lengths of the buffy coat layers. The layers are measured in a manner that is similar to that used for measuring PCV. Results of QBCA of blood samples from dogs, cats, and horses indicated that the hematologic values obtained correlated with results obtained by use of conventional methods. The accuracy and ease of use of QBCA and the availability of results while the animal is still being examined make QBCA a useful tool for hematologic evaluation of animals.