Influence of turbidity on photometric assays: a blank sample must always be used

The authors studied the influence of sample turbidity on photometric assays at different wavelengths. Turbidity was created by using a mixture of hydrazine sulfate and hexamethylene tetramine, and a dye solution (p-nitrophenol, cobalt nitrate). This work demonstrates the necessity of using a bland sample, for example in the glucose assay (glucose oxidase/peroxidase). The influence of turbidity on an assay depends upon the instrument. Knowledge of this influence is essential for the evaluation of the viability of an assay in hyperlipemic serum.