1994 Volume 23 Issue 2 Pages 164-169
A new, totally enzymatic method for the determination of inulin in serum and urine, using inulase (EC 3.2.1.7.), fructokinase (EC 2.7.1.4), phosphoglucoisomerase (EC 5. 3. 1. 9), and glucose- 6- phosphate dehydrogenase (EC 1. 1. 1.49) is described.
The assay is carried out by means of a fructose determination after hydrolysis of inulin with inulase.
The calibration curve was linear up to 2g/l of inulin. The within- run coefficients of variation were found to be between 1.1 and 2.3%.
Data showing the consistent quantitative recovery of added inulin from serum and urine are presented.
Thirty-seven serum-urine samples for renal glomerular filtration rate were used to obtain correlations between this method (Y) and the thiosulfate method (X). The correlation coefficients and regression equations were as follows r=0.9785, Y=0.8902X-0.92.
This method is simpler and faster than those used in the past, and has shown itself to be practical for use in clinical laboratories.
