Effect of Three-Day Refrigerated Storage on the Accuracy and Analytical Reliability of Complete Blood Count Parameters in Clinical Laboratories

Abstract

Introduction: The complete blood count (CBC) is among the most routinely ordered tests in clinical medicine. When immediate processing is unavailable, blood specimens are refrigerated to preserve samples. Whether prolonged cold storage compromises the accuracy of CBC measurements remains a concern for laboratory practice.

Objective: To determine how three-day refrigerated storage at 2–8°C affects the accuracy and analytical reliability of CBC parameters in a clinical laboratory setting.

Methods: Seventy-five venous blood specimens collected into EDTA tubes were divided into three groups of 25, analyzed at 24, 48, and 72 hours after collection. An automated hematology analyzer measured hemoglobin (Hb), red blood cells (RBC), white blood cells (WBC), platelets (PLT), and red cell indices (MCH, MCHC, RDW). One-way ANOVA with p < 0.05 was used to evaluate differences between groups.

Results: There was no statistically significant difference in hemoglobin levels across the three storage times (p > 0.05). On the other hand, RDW and RBC indices (MCH, MCHC) showed substantial changes (p < 0.05). WBC and platelet counts showed a gradual reduction, with significant differences (p < 0.01). These results suggest that leukocytes and platelets are especially vulnerable to extended refrigeration.

Conclusion: Three-day refrigerated storage compromises the reliability of several CBC parameters, most notably WBC and platelet counts. CBC analysis should be performed within 24 hours of sample collection to ensure result accuracy.