Lower Sample Volumes Collected Into Spray-Dried K2EDTA Vacuitaner Bottles Are Suitable For Automated Complete Blood Count Analysis Including Differential Leukocyte Count

Abstract

Collection of lower sample volumes into dipotassium ethylenediaminetetraacetic acid (K2EDTA) containers, according to the manufacturers' data and current Clinical and Laboratory Standards Institute, results in erroneous haematology results. To proof this we collected acceptable limit of lower sample volumes for haematology analyses into the 4.0ml standard spray-dried K2EDTA. 9.0ml of blood from 15 retroviral volunteers was collected and each donation was aliquot into the following volumes 4.0, 2.0, 1.5, 1.0, 0.5ml. These samples were analyzed within 4hrs of collection on Sysmex KX-21N haematology analyzer for complete blood count (CBC) including leukocytes differentials. T-test showed there was no significant difference between results of lower samples volumes and the standard volume and regression analysis showed excellent correlation for all parameters. Lower sample collection volumes compared to the standard volume showed negative bias for platelet count but the difference was considered insignificant with percentage differences of 4.6%, 3.0%, 2.9%, and 1.7% for 1.0, 1.5, 0.5, and 2.0ml collection volumes respectively. Flag messages were noticed in about 67.0% of the patients irrespective of collection volumes. Acceptable CBC values for spray-dried K2EDTA collection tubes containing lower sample volumes can be obtained with as little as 1.0ml in Nigerian subjects.