We developed and evaluated a colorimetric method for enzymic determination of guanidinoacetic acid (GAA) in urine. Endogenous urinary urea was first eliminated by urease (EC 3.5.1.5), and the added urease was then removed from the sample by centrifugal ultrafiltration. GAA in the ultrafiltrate was subsequently hydrolyzed by guanidinoacetate amidinohydrolase (EC 3.5.3.2) to glycine and urea. The...

Non-esterified cholesterol was determined enzymatically with the cholesterol oxidase-peroxidase reaction using phenol and 4-aminophenazone as chromogens. This assay as done in the supernatant containing the lipoprotein-X. Other serum lipoproteins were removed by precipitation with heparin and zinc acetate followed by centrifugation. No standardization was required, the lipoprotein-X concentrati...

A simple and cost effective spectrophotometric method was described for the determination of Ertapenem (ERP) in pure form and in pharmaceutical formulations. The method is based on the formation of dark yellow colored chromogen when the drug reacts with P-dimethyl amino benzaldehyde (PDAB) reagent. The method involves the condensation of the imino substitutes of the drug with PDAB at the λmax 5...

A novel molecular method for HIV-1 proviral DNA detection comprising two main techniques: nested PCR, amplifying a target sequence of the ENV-gene of HIV-1, and nonradioactively-reversed probe hybridization for the detection of the amplified target sequence. The dual amplification of inserted HIV-1 proviral DNA in each DNA sample to be tested was performed by nested PCR in two steps: firstly wi...

This paper describes a comparison of two analytical techniques, one employing bathophenanthrolinedisulfonate (BPT), a most commonly-used reagent for Fe (II) determination, as chromogen and an electrothermal atomic absorption spectroscopy (ETAAS) for the quantification of non-transferrin bound iron (NTBI) in sera from thalassemic patients. Nitrilotriacetic acid (NTA) was employed as the ligand f...

A DNA probe specific for Listeria monocytogenes was isolated from a beta-hemolytic recombinant clone of an L. monocytogenes gene bank. It was labeled with horseradish peroxidase and used in a direct colony hybridization method on hydrophobic grid-membrane filters for the detection of the organism. Following color development of the chromogen, a commercial counter (HGMF Interpreter) was able to ...

We describe a new enzymic colorimetric method in which urea is measured in serum by use of a single reagent mixture. Ammonia produced by urea hydrolysis, catalyzed by urease, reacts with glutamate and ATP in the presence of glutamine synthetase. The ADP so produced is assayed in reactions catalyzed sequentially by pyruvate kinase and pyruvate oxidase in a system that generates hydrogen peroxide...

We describe a new colorimetric method for measuring creatinine in serum and urine. Creatinine hydrolysis is catalyzed by creatinine amidohydrolase, and the creatine so produced is assayed in reactions catalyzed sequentially by creatine amidinohydrolase and sarcosine oxidase in a system that generates hydrogen peroxide. The hydrogen peroxide is measured at 510 nm in a reaction catalyzed by horse...

A method is described for analysis of gangliosides by GLC assay of the sialic acid component. Mild acid treatment in methanol converted the latter to methyl ketoside methyl ester, which was then chromatographed as the TMS derivative. The major methanolysis product was shown to be the beta-anomer, and its chromatographic peak was used for quantification. NANA and NGNA could be analyzed simultane...

Simple spectrophotometric and spectrofluorimetric methods are suggested for the determination of antifungal drugs; clotrimazole, econazole nitrate, ketoconazole, miconazole and tolnaftate. Spectrophotometric one depends on the interaction between imidazole antifungal drugs as n-electron donor with the pi acceptor 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in methanol or with p-chloranilic ...