A Linear Single Reagent Method for Determination of Protein in Cerebrospinal Fluid

Abstract

The use of Ponceau S for the determination of protein in cerebrospinal fluid was recently published by Pesce & Strande (Clin. Chem. 19, 1265, 1973). This metod is further improved by decreasing the concentrations of trichloroacetic acid and Ponceau S, and by measuring the decrease of absorbance caused by proteins. A fast and precise method was developed. Full analysis can bedone in 5 minutes with a mean precision (CV%) about 1.5%. Only one stable reagent is needed and the sample volume is 50 μ. Two modifications are presented; one suitable only for digital photometers covers a linear range up to 2500 mg/l, and the other for analog photometers is linear up to 1350 mg/l.

Key Words:

• Body fluid proteins
• dye binding
• micromethod
• Ponceau S
• protein analysis
• spinal fluid