Hemoglobin Constant Spring exhibits prolonged ex vivo stability when assessed by HPLC.

Objectives: 1) To investigate the presence of hemoglobin Constant Spring (HbCS) in a patientwith severe microcytic anemia who had previously been diagnosed with alpha thalassemia minor. 2) To assess the stability of HbCS post blood collection by high performance liquid chromatography (HPLC).
Design and Methods: Hemoglobin fractionation was performed by HPLC immediately after specimen collection using the β-thalassemia Short Program on the BioRad Variant II. To assess HbCS stability, the patient's specimen was re-analyzed over a 17 day period.
Results: HPLC analysis showed a low abundance peak with chromatographic properties consistent with HbCS. Presence of this hemoglobin variant was confirmed by electrophoresis and gene sequencing. HbCS remained detectable by HPLC for 17 days after specimen collection, with minimal degradation.
Conclusions: Our results suggest that HbCS is stable many days after blood collection. Consequently, it is not necessary to analyze specimens immediately after collection when assessing the potential presence of this hemoglobin variant.
(Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.)