Refrigerated storage improves the stability of the complete blood cell count and automated differential.
A CBC count was performed on 113 random patient and 21 control specimens before and after 24-hour room temperature (RT) storage; 98 random patient and 20 control specimens also were analyzed before and after 24 hour 4 degrees C storage. The Cell-Dyn 3500 (Abbott Laboratories, Abbott Park, IL) was used for analysis. RT storage showed a decline in WBC count using the optical but not the impedance method, resulting in a large number of WBC flags. An increase in mean corpuscular volume also was seen for patient specimens. The automated WBC differential showed a decrease in the percentage of neutrophils and an increase in the percentage of lymphocytes, owing primarily to neutrophil degeneration. These changes also were seen in the manual differential to a similar degree. Storage of specimens at 4 degrees C largely prevented all of these changes. The implementation of refrigerated specimen storage is a simple, inexpensive method to improve the accuracy of CBC results for aged specimens on automated hematology analyzers.
Wood
B L
BL
Department of Laboratory Medicine, University of Washington, Seattle, USA.
Andrews
J
J
Miller
S
S
Sabath
D E
DE
D001322:Autoanalysis / Q000295:instrumentation; D001793:Blood Preservation / Q000379:methods*; D015925:Cryopreservation / Q000379:methods*; D005069:Evaluation Studies as Topic; D006405:Hematology / Q000295:instrumentation; D006801:Humans; D007958:Leukocyte Count; D011897:Random Allocation; D012034:Refrigeration; D015203:Reproducibility of Results; D013696:Temperature