Comparison of the Anthrone Reagent and a Copper-Reduction Method for Determining Blood Sugar in Calves

Abstract

Protein-free filtrates from 1,500 samples of blood from 12 calves were prepared according to Folin-Wu. An aliquot of each filtrate was analyzed for blood sugar by both the anthrone reagent and the Somogyi-Nelson technique. The anthrone procedure is as follows: Pipet 1 ml. of sample filtrate, blank, or standard into a test tube and chill; add 10 ml. of ice-cold 0.05% anthrone dissolved, in 72% sulfuric acid to each test tube while immersed in ice water and mix. After equalizing the temperature of the tubes in a tap-water bath, place them in a boiling water bath for 10 min.; cool in a running tap-water bath. Pour the reactants into matched spectrophotometer cuvettes and read at a wavelength of 620 mµ after aging for one-half hour in the dark. Statistical analysis indicated that the difference between the two techniques was highly significant. The anthrone values were less than 5% greater. The correlation coefficient between the results of the two methods was 0.94. The inherent error in both methods was the same, as indicated by almost identical standard deviations. © 1961, American Dairy Science Association. All rights reserved.