Comparison of Biuret and Refractometry Method for Serum Total Protein Measurement in Cattle and Goat

Abstract

Abstract Objectives The biuret method is frequently used to determine serum total protein. On the other hand refractometer, a quicker and less expensive option is also determine serum protein. However no study was conducted in Ethiopia to determine validity of refractometer Therefore the purpose of this study was to compare the serum total protein concentration measurement in cattle and goats obtained by the biuret method and refractometer. Results Serum samples from 60 cattle and 60 goats were assayed by both methods and data analyzed with a paired t-test, Pearson’s correlation, and Bland-Altman plots. There was a strong correlation between the total protein values determined with the refractometer and the biuret method in cattle (r= 0.9332) and goats (r = 0.9746). There were no significant variations in the protein values measured with the refractometer and those evaluated with the biuret method in both species (P> 0.05). Bland-Altman plots showed that biases indicating the analytic and user error were 8.33% in both species which is below the acceptable total error (<10%). Thus refractometer can be used in place of biuret method since it was valid enough to measure serum total protein in cattle and goats.