A method for the estimation of inulin in plasma and urine containing dextran.

Simultaneous determination of glomerular filtration rate by inulin clearance may be required during studies of the renal excretion of the bacterial polysaccharide, dextran. This involves the estimation of both inulin and dextran in the same plasma and urine samples. Unfortunately, dextran interferes with the analysis of inulin, both by the method of Alving, Flox, Pitesky, and Miller (1) and by that of Roe, Epstein, and Goldstein (2). A modification of the method of Roe et al. (2) is here proposed, in which dextran is removed by precipitation from ethanolic solution. This allows inulin to be estimated without interference.