Significance of dilution errors in the measurement of erythrocyte sedimentation rate

Abstract

Erythrocyte sedimentation rate test (ESR) by the Westergren method involves the use of a blood sample, anticoagulated and diluted 4:1 with sodium citrate solution. Dilutions are made during sample collection. However, the method invariably leads to errors in the dilutions. This study was done to assess the effects of these dilution errors on the results of the ESR test. The results indicate that the under diluted samples sedimented faster and the over diluted samples slower than standard dilutions, resulting in significant errors in the ESR readings.