An extensive direct assay in biological assay

An ln vivo Assay for Biological Activity of Synthesized Recombinant Human Growth Hormone

An enzymic creatinine assay and a direct ammonia assay in coated thin films.

We developed a thin-film enzymic assay for creatinine that makes use of creatinine iminohydrolase (EC 3.5.4.21) to convert creatinine to N-methylhydantoin and ammonia. The ammonia diffuses through a semipermeable layer and is quantitated by reaction with bromphenol blue. A paired analysis of the sample on a separate coating without the enzymic reaction measures endogenous ammonia and, for sampl...

Hyaluronidase: correlation between biological assay and other methods of assay.

Different workers have at various times sought to correlate the in vivo and in vitro activities of hyaluronidase preparations. Chain & Duthie (1940), drawing attention to the association between diffusion in the tissues and the mucolytic activity of testicular extracts, pointed out that the viscosityreducing and diffusing activities of various enzyme preparations were in good agreement. McClean...

Direct renin assay and plasma renin activity assay compared.

substances produced an interference 5% compared with the serum diluted with drug cocktail diluent. The list of drugs tested appears in Supplement 1, which accompanies the online version of this Technical Brief at http:// www.clinchem.org/content/vol50/issue11/. Ion suppression was assessed as recommended by Annesley (12 ). Briefly, the response of calibrators injected into the mobile phase was ...

The Biological Assay of Carcinogens

Many experiments have been described in which a batch of animals are painted or injected with a carcinogen, and the dates recorded when warts or malignant growths are detected. The object of such experiments is usually to compare the potency of different carcinogens, or of different doses or methods of application, or else to compare the sensitivity of different batches of animals to a given ca...