234 CLINICAL CHEMISTRY, Vol. 32, No. 1, 1986 basic chemical principles. Reviewing uric acid methodology, we discovered one incorrect and two unbalanced reaction equations for uric acid analysis by the uricas&peroxidase-phenol-4-aminoantipyrine method. Figure 1 illustrates the overall reaction. An investigator has incorrectly prothe formation of a dichloro-oquinoneimine dye from the reaction bet...

In this automated single-run enzymatic procedure for specific determination of triglycerides in serum, free glycerol is removed from the reaction mixture by pre-incubation with glycerol phosphate oxidase and peroxidase. The subsequent addition of lipase and the chromogen, 4-aminoantipyrine, results in the formation of color proportional to the amount of triglycerides in serum. Standards contain...

The assay of multiple analytes in a single aliquot can be advantageous from both measurement and economic standpoints. The objective of this study was to develop a simple and sensitive microenzymatic method for the determination of three biologically important lipids. Triglycerides (as glycerol), phospholipids (as choline), and total cholesterol (as unesterified cholesterol) were assayed, in th...

We demonstrate a technique that uses microdroplets for culturing and selecting bacterial cultures in a model biotechnological application. We propose an assay for determination of ethanol concentration that provides increased dynamic range and is compatible with droplet microfluidic screening technologies. The assay comprises two enzymes—alcohol oxidase (AOX) and horseradish peroxidase (HRP)—an...

A 3D-printed microfluidic device was designed and manufactured using a low cost ($2000) consumer grade fusion deposition modelling (FDM) 3D printer. FDM printers are not typically used, or are capable, of producing the fine detailed structures required for microfluidic fabrication. However, in this work, the optical transparency of the device was improved through manufacture optimisation to suc...

A sensitive, specific, and simple method for determining serum or urine arylesterase (EC 3.1.1.2) is described. The enzyme acts on phenyl acetate to release phenol, which produces a stable indophenol dye with 4-aminoantipyrine and potassium ferricyanide. Arylesterase, a thiol enzyme, is reactivated by 2-mercaptoethanol and by cysteine, but not by reduced glutathione. Calcium is indispensable to...

Activated carbon appended with organic groups was obtained by a grafting technique using a one-step reaction with diazonium salts. Using the organic aryl amines of 4-bromo aniline and 4-aminoantipyrine as precursors for the corresponding functional diazonium reagents, the bromobenzene and antipyrine molecules were bonded to the surface of carbon. The modified activated carbon was characterized ...