Abstract
Low protein solutions, such as cerebrospinal fluid and urine must be concentrated prior to paper electrophoretic analysis of their protein fractions. Methods for the concentration of low protein solutions by dialysis against concentrated solutions of polyvinylpyrrolidon, gummi arabicum and Carbowax 6000, were successfully applied to highly diluted sera without significant changes in their protein fractions. Care must be taken to avoid the contamination of protein solutions by low molecular weight substances contained in Carbowax 6000.
