Measurement of a glycoprotein with blood group A activity by light scattering

A light scattering method for quantifying glycoproteins is presented. Conditions of ethanol concentration, wavelength, time of reading, and sample and reagent volumes have been examined. The definitive assay involves addition of 9 vol absolute ethanol to 1 vol sample, mixing, and readings at 105 degrees angle at the interval between 10 and 13 min after placing the cell into the photometer. The obtained values are temperature-dependent. Thus, temperature control is essential. In this assay, a concentration range of 10-60 micrograms glycoprotein has been used. As described, the method is independent of the chemical composition of the different glycoproteins and is barely influenced by size and shape of glycoproteins.