Analysis of time and temperature stability of EDTA anticoagulation whole blood for complete blood count parameters with the use of Abbott CELL-DYN Sapphire hematology analyzer

Stability and comparison of complete blood count parameters between capillary and venous blood samples

INTRODUCTION

This study assessed the comparability of complete blood count (CBC) parameters between capillary and venous samples, and extended previous research by examining the influence of different storage temperatures on CBC stability up to 7 days after sample collection.

METHODS

Venous and capillary blood samples were collected from 93 adult patients. Hemoglobin (Hb), hematocrit (Ht), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean platelet volume (MPV), leukocytes, lymphocytes, basophils, eosinophils, erythrocytes, red cell distribution width (RDW), immature granulocytes (IG), immature reticulocyte fraction (IRF), monocytes, neutrophils, platelets, and reticulocytes were measured. Deming regression and mean relative differences between venous and capillary measurements were contrasted with desirable total allowable error (TEa). Stability was assessed in 20-27 venous blood samples stored at 4, 21-22, or 30°C, and analyzed at 0, 24, 48, 72, 96, 120, 144, and 168 h. Mean relative change with respect to baseline measurements was compared to the desirable TEa to determine acceptable stability.

RESULTS

Deming regression demonstrated strong linear correlations and acceptable variation between venous and capillary measurements. Erythrocytes, Hb, Ht, MCH, MCV, RDW, reticulocytes, and platelets showed acceptable stability for at least 96 h at 4°C. Mean relative change exceeded desirable TEa after 24 h at 30°C for all parameters, except erythrocytes, Hb, leukocytes, and MCH.

CONCLUSION

Clinical laboratory specialists and clinicians should be aware of potential differences between venous and capillary measurements, and the influence of storage conditions. Clinical validity of delayed CBC analysis depends on the clinical situation and required precision of the result.

Effect of environmental conditions on bloodstain metabolite analysis

Establishing a correlation between environmental variables and chemical change can significantly improve the quality of research in multiple fields. Among various environmental variables, temperature and humidity are closely related to the rate of chemical reactions. This study aimed to confirm changes in metabolite markers that were previously discovered in other temperature and humidity environment conditions and to confirm the possibility that they could act as markers. After blood collection from the subjects and bloodstain preparation, the quantitative values of the bloodstain metabolites were confirmed (when the age of the bloodstain was within a month) under eight environmental conditions (4 °C/30%, 4 °C/60%, 25 °C/30%, 25 °C/60%, 25 °C/90%, 40 °C/30%, 40 °C/60%, and 40 °C/90%). Age-of-bloodstain estimation models were constructed to confirm the applicability of bloodstain metabolites as markers for bloodstain age in various environments. The average concentration of metabolite markers exhibited a decreasing trend with the age of the bloodstain, which transformed into an increasing trend from day 7 onwards. In terms of temperature and humidity, 25 °C and 90%, respectively, showed the most dissimilar metabolite change pattern compared to other conditions. The age-of-bloodstain estimation models developed here have an R-square value of up to 0.92 for each condition and an R-square value of 0.71 when all environmental conditions were combined. The findings herein highlight the immense potential of blood metabolites for field application, confirming the possibility of predicting metabolite changes from the rates of their chemical reactions and validating the importance of metabolites as age-of-bloodstain markers under various environmental conditions.