Enzyme tests

Enzyme resin Pen G-Acylase immobilized on 60 240- 150 1080 8-3 Enzyme activity Enzyme test... 

The diagnostic usefulness should be established by appropriate retrospective or prospective studies to see if the test in fact improves the diagnostic accuracy. For inherited enzyme diseases, the measurement of the enzyme activity can be diagnostically specific and highly useful. For otherwise obvious diseases such as metastatic prostatic carcinoma, enzyme tests may be of little value (24). 

Tor [7] developed a new method for the preparation of thin, uniform, self-mounted enzyme membrane, directly coating the surface of glass pH electrodes. The enzyme was dissolved in a solution containing synthetic prepolymers. The electrode was dipped in the solution, dried, and drained carefully. The backbone polymer was then cross-linked under controlled conditions to generate a thin enzyme membrane. The method was demonstrated and characterized by the determination of acetylcholine by an acetylcholine esterase electrode, urea by a urease electrode, and penicillin G by a penicillinase electrode. Linear response in a wide range of substrate concentrations and high storage and operational stability were recorded for all the enzymes tested. 

It seems to be important that in myocardial infarction no increase of GSSGR activity could be found (K6, LI), thus representing the possibility for differential diagnosis in connection with other enzyme tests. 

BUN and serum creatinine levels and hepatic enzyme test... 

Decarboxylase activity The decarboxylation of benzoylformate was studied using a coupled enzyme test as described previously [4]. 

As depicted in Table 2.2.7.2, a,P-unsaturated alkenones possessing the Z configuration are only poorly accepted by the enzymes tested. In addition, with these substrates only low enantioselectivity was observed for the reduction step. 

The FDA approves the diabetes drug Rezulin for sale, but by the end of the year evidence that Rezulin causes liver failure leads the FDA to recommend that patients taking the drug undergo regular liver enzyme tests to identify any problems. 

Many of the enzymes tested had a molecular weight of less than 100,000. That of the S. purpurascens enzyme13 was 495,000, and those of the Sclerotinia fructigena enzymes23 were 200,000 and 350,000. 

The most important features are, first, that some of the a-amylases— i.e., those in digests Numbers 4, 5, 6, and 7 have catalyzed glycosylations from a-maltosyl fluoride at one-tenth to one-one hundredth the enzyme concentrations required for action on a-D-glucosyl fluoride. The Aspergillus oryzae a-amylase, which had the weakest synthetic action on a-D-glucosyl fluoride of the enzymes tested at 100 ftg/ml, has produced under conditions of this experiment an extended series of maltosaccharides at 1 fig/ml. 

Buffer used for enzyme test solution e.g., 50 to 100 mM TrisCl, pH 7.8 to 8.6 containing 10 mM CaCl2 (see recipe for assay buffer)... 

Add 10 pi of 0.1 to 5 pM enzyme test solution and mix well with a small plastic spatula or by placing a small piece of Parafilm over the cuvette and inverting several times. 

The optimal concentration of the enzyme test solution depends on the proteinase being assayed, and must be determined experimentally. For chymotrypsin, 2.5 to 25 pg/ml (0.1 to I pM) is appropriate. Concentrations of 5 to 50 pg/ml are appropriate for most proteinoses assayed with this procedure. 

When the level of enzyme activity or concentration is low, it may be necessary to change the composition of the assay mixture to increase the amount of enzyme test solution added (e.g., using 910 pi assay buffer, 40 pi substrate, and 50 pi enzyme test solution). 

McCleary, B.V., Gibson, T.S., Solah, V., and Mug-ford, D.C. 1994. Total starch measurement in cereal products Interlaboratory evaluation of a rapid enzymic test procedure. Cereal Chem. 71 501-505. 

II form since it had been prepared from wood a-cellulose. Of all the Cx enzymes tested, that induced on Avicel showed the lowest capacity for degrading cotton when it was acting in synergism with the Cx induced on cotton. 

The maximum reaction rate rmax is proportional to the enzyme concentration within the range of the enzyme tested. 

GDH, GS, and malate dehydrogenase (MDH) activities have been also studied in carrot cells suspensions (Muscolo et al., 1999). All enzymes tested were positively affected by the humic fraction with low molecular weight. The activities of GDH,... 

The case study presented here was conducted by the Environmental Research Centre, CIMA, Faculty of Sciences, of the University of La Plata. The more frequently applied tests were those conducted with the Lactuca sativa seed germination assay, followed by the Hydra, Daphnia and Selenastrum tests. They were used for the assessment of toxicity from hazardous wastes and waste leachates, sediment pore water and sediment leachates, surface waters and groundwater. An additional test based on (3-galactosidase (in vitro-free enzyme test) inhibition, known for its sensitivity to metals (Apartin and Ronco, 2001), was also incorporated in the battery. 

L15. Lott, J., Enzyme tests in gastroenterology. In Enzyme Tests in Diagnosis (D. W. Moss and S. Rosalki, eds.), pp. 60-89. Oxford University Press, New York, 1996. 

T6. Titz, N. W., Support of the diagnosis of pancreatitis by enzyme tests—Old problems, new techniques. Clin. Chem. Acta 257, 85-98 (1997). 

Urease (EC 3.5.1.5 Type IX, Sigma-Aldrich from Jack Beans) was used throughout the experiments. Before immobilizing urease onto the microreactor systems, the enzyme was evaluated for activity in the chosen buffer system (Tris[hydroxymethyl]aminomethane [THAM]). Free enzyme tests of the urease showed an approximate activity of 44,800 U/g of solid. 

The procedure is repeated using the enzyme test solution, where Nti and Na are the volumes of 0,02 N NaOH consumed, Na referring to the blank titration. 

Forensic biochemists perform blood typing and enzyme tests on body fluids in cases involving assault, and also in paternity cases. Even tiny samples of blood, saliva, or semen may be separated by electrophoresis and subjected to enzymatic analysis. In the case of rape, traces of semen found on clothing or on the person become important evidence the composition of semen varies from person to person. Some individuals excrete enzymes such as acid phosphatase and other proteins that are seldom found outside seminal fluid, and these chemical substances are characteristic of their semen samples. The presence of semen may be shown by the microscopic analysis for the presence of spermatozoa or by a positive test for prostate specific antigen. 

Results in these schemes are from preliminary enzyme testing and reactions are not optimized. Note that yields are based on chromatographic results, not isolated products. 

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