CLSI H07-A3

NCCLS document H7-A3 – Procedure for Determining Packed Cell Volume by the Microhematocrit Method describes a standard method for direct measurement of packed cell volume (PCV). The standard is intended for reference use by clinical laboratory personnel and by manufacturers of instruments that determine PCV. The method can also be used (with appropriate precautions as described in the document) in the clinical laboratory for diagnostic purposes, for monitoring a patient’s response to therapy, and for evaluating instruments and other methods for determining PCV; the standard should be used for whole blood calibration procedures of hematology analyzers. The document gives detailed specifications of the materials to be used in the procedure, contains information for calibrating the centrifuge and reading device, and includes information on verification of calibration. Expression of results, generally accepted reference values, and potential sources of error are given.