Beta-lactoglobulin is the control provided in the kit. In the food industry, protein aggregation is a desired attribute since aggregates impart favorable texture. So, it is possible to use the assay with properly diluted samples as long as the sample is not too viscous. The effective protein concentration range for the test protein is less than 1mg/ml. There is no upper limit but fully aggregated protein above 20 mg/ml would saturate the dye.