New sandwich ELISA for human urinary N-acetyl-beta-D-glucosaminidase isoenzyme B as a useful clinical test.
We have developed a new ELISA for quantifying N-acetyl-beta-D-glucosaminidase (NAG) isoenzyme B in human urine after raising monoclonal antibodies against the isoenzyme from human placenta. Though the obtained antibodies reacted not only to isoenzyme B but also to A, we could detect isoenzyme B selectively by a two-step sandwich ELISA with a pair of selected antibodies at low pH in the first reaction. The detected limit was 0.5 microgram/L for a sample volume of 25 microL. Within-run CVs ranged from 2.5% to 5.4% and between-run CVs ranged from 6.2% to 9.1%. Recoveries of NAG isoenzyme B added to each of three urine samples ranged from 91% to 114%. The dilution curves of urine samples showed good linearity. The cross-reactivity of NAG isoenzyme A was practically negligible (2-3%). The mean value for NAG isoenzyme B in spot urines from healthy adults was 2.9 micrograms/g creatinine. This ELISA method is rapid and precise enough for routine determination of NAG isoenzyme B in human urine.
Numata
Y
Y
Diagnostic Science Department, Shionogi & Co., Ltd., Osaka, Japan.
Morita
A
A
Kosugi
Y
Y
Shibata
K
K
Takeuchi
N
N
Uchida
K
K
D000118:Acetylglucosaminidase / Q000276:immunology / Q000302:isolation & purification / Q000652:urine*; D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000276:immunology; D002852:Chromatography, Ion Exchange; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000276:immunology / Q000302:isolation & purification / Q000652:urine*; D007674:Kidney Diseases / Q000201:enzymology; D008297:Male; D010920:Placenta / Q000201:enzymology; D012016:Reference Values; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D000941:Antigens; D007527:Isoenzymes; D000118:Acetylglucosaminidase