The fluorometric coupled enzyme assay to measure phosphatidic acid (PA) involves the solubilization of extracted lipids in Triton X-100, deacylation, and the oxidation of PA-derived glycerol-3-phosphate to produce hydrogen peroxide for conversion of Amplex Red to resorufin. The enzyme assay is sensitive, but plagued by high background fluorescence from the peroxide-containing detergent and inco...

The 2-aminothiophenol-based fluorometric assay of Nakano et al. (1973, J. Pharm. Soc. Jpn. 93, 350-353) for monosaccharides has been modified to improve the speed, applicability, and sensitivity of the method. The improved assay is applicable to complex carbohydrates as well as to monosaccharides. Less than 50 ng of carbohydrate in a final volume of 2 ml can be quantitatively measured within 30...

OBJECTIVE Easy tool for newborn screening of Gaucher and Hurler diseases. METHODS Method comparison between fluorometric enzymatic activity assay on a digital microfluidic platform and micro-titer plate bench assay was performed on normal (n = 100), Gaucher (n = 10) and Hurler (n = 7) dried blood spot samples. RESULTS Enzymatic activity analysis of glucocerebrosidase (Gaucher) and α-l-iduro...

Aristolochic acid is a natural product with possible implication in Balkan endemic nephropathy. A convenient fluorometric assay for the compound is described based on reduction to the lactam and measurement of the intensity of fluorescence. The limit of sensitivity was 0.05 mug/ml. A GLC assay is also described, based on flash methylation of aristolochic acid and its lactam using trimethylanili...

Niemann-Pick-A/B disease is a lysosomal storage disease caused by deficiency of acid sphingomyelinase (1 ). Efforts are underway to develop novel therapies for this disease, and some newborn screening centers have started to test for acid sphingomyelinase enzymatic activity in dried blood spots on newborn screening cards. Available assays for newborn screening include tandem mass spectrometry (...