A method for determining the concentration of haptoglobin in cattle blood following haemolysis caused at collection

This study aimed to develop an in-house assay for haptoglobin determination in bovine blood samples, assess the effect of haemolysis on the reported haptoglobin concentration and develop a method to correct for haemolysis interference. The assay developed is highly repeatable (92.3% across plates and 94.8% between assays). A correction equation (Hpcorrected=Hpraw-Hpendogenous activity-Hpdue to HbHpcorrected=Hpraw-Hpendogenous activity-Hpdue to Hb; where Hpdue to Hb=0.118×Hbfree+0.015Hpdue to Hb=0.118×Hbfree+0.015) was developed based around the linear relationship of haptoglobin and haemoglobin (by-product of haemolysis) and endogenous interference, tested and validated for use with haemolysed samples. The method described in this paper allows samples inadvertently haemolysed at collection to be analysed, with the reported haptoglobin concentration being an accurate reflection of the physiological levels in the animal’s blood at the time of collection.