Laboratory Investigation of Rubella

Abstract

obtained with positive samples may be reduced to near reagent blank values in this way and false-negative results obtained. Careful mixing of the contents of the tube by gentle inversion two or three times after the addition of the CPC reagent and again immediately prior to reading the absorbance is essential to obtain consistent results. This test can be used as the initial discriminatory procedure in the investigation of mucopolysaccharidoses and it is important that other users performing this test are made aware that the "insoluble" CPC-precipitable mucopolysaccharide can redissolve if not handled carefully. This could also be a source of error in the quantitative hexuronic acid method' for estimating mucopolysaccharides, which also has an initial CPC precipitation step.