Bone Marrow Cell Counting: Methodological Issues

This chapter discusses techniques for quantitating the cellular content of peripheral blood and bone marrow and addresses the methodologic issues confronted by laboratories carrying out cell counting in conjunction with bone marrow processing for transplantation. Harvested marrow filtered by this or comparable methods should consist of an anticoagulated single cell suspension, but will also contain occasional cell clumps and fat globules, as well as hemolyzed red blood cells and other noncellular contents from the admixed peripheral blood. Automated electronic counting of peripheral blood samples is considered accurate for leukocytes, platelets, and erythrocytes and has been shown to have higher precision than manual counting methods, with CVs in the 1 to 3% range, compared with 10 to 15% for manual counting. Hemoglobin content of peripheral blood may be measured by manual or, more commonly, by automated methods based on the light absorbence at 540 nm of cyanmethemoglobin, a stable conversion product of all forms of hemoglobin.