BACKGROUND Estimation of urinary oxalate is one of important tools for the diagnosis and treatment of urolithiasis. And more precise, simple and inexpensive method is desirable. In the present study, we evaluated three methods which were clinically well-used. METHODS From October 1996 to June 1997, 146 acidified urine samples were collected for 24 hours from 144 urolithiasis patients. We dete...

One of the main factors limiting agricultural production in tropical climate regions is mainly related to the presence of exchangeable aluminum (Al) in highly weathered acid soils. Four methods of Al determination extracted with neutral 1 mol L KCl solution were evaluated: three colorimetric methods (aluminon plus ascorbic acid, and eriochrome cyanine R by FIA) and the usual titrimetric method ...

In the estimation of very small q-qantities of material there is no question that colorimetric is preferable to gravimetric analysis. The colorimetric method is generally quicker and simpler to carry out-an important factor when numerous analyses are involvedand it is not subject to the manipulative errors incurred in dealing gravimetrically with minute amounts of material. The method, however,...

We presented the colorimetric and electrochemical methods for determination of the dipeptidyl peptidase-IV (DPP-IV) activity and screening of its inhibitor using gold nanoparticle (AuNP) as the probe. In the colorimetric assay, the substrate peptide with a sequence of Arg-Pro-Arg induced the aggregation and color change of AuNPs, whereas cleavage of the peptide by DPP-IV prevented the aggregati...

AIMS To validate a method of assessment of low hepatic iron concentration based on a biochemical colorimetric assay plus histological scoring. METHODS The within-day and day to day precision of the iron colorimetric assay was determined on frozen rat liver. The coefficient of variation (CV) of iron measurement in two separate samples from the same liver was determined for 21 deparaffinised hu...

VARIETY of methods is available for tue colorimetric determination of uric acid. In general, these are based on precipitation of proteins, followed by the reduction in an alkaline medium of phosphotungstate by the uric acid ill the protein-free filtrate. Results of colorimetric determinations may at times vary from “true” uric acid values as determined by unease methods. This is because the col...

Two radiochemical (Irosorb 59 and Res-O-Mat Fc), a mechanized (DSA 560) and several manual colorimetric procedures (test combination of Roche, Merck and Haury) for the determination of the total iron binding capacity were compared with the transferrin-binding capacity (immunoprecipitation). Whereas all methods show a satisfactory correlation with the transferrin concentration, most colorimetric...

A novel colorimetric method to quantify tannase activity of viable tannase-producing bacterial strains was developed through application of a visual reading method that was to detect the activity qualitatively. The novel method was sensitive enough to quantify the marginal tannase activity of strains that could not be otherwise measured by conventional spectrophotometric or colorimetric methods.