A colorimetric method for the determination of free haemoglobin in human serum is described, using 4-aminophenazone as chromogen, and commercially available haemiglobin cyanide solutions as standards. The reaction system is suitable for manual measurements as well as determinations with a centrifugal analyser (Cobas Bio System). Accuracy, linearity and stability of the procedure is shown. A ref...

Primycin is a macrolide antibiotic complex produced in microbiological fermentation processes. The microbial production of primycin requires an in-process analytical method suitable for monitoring the level of the active agents. In this paper, a method fulfilling the described requirement is presented. This method consists of a simple, efficacious extraction step, an instrumental sample applica...

The 1-H nuclear magnetic resonance spectrum of living tunicate blood cells was examined in an attempt to develop a biophysical assay for the native vanadium chromogen. The living cell spectrum was found to exhibit a broad 21 ppm downfield Gaussian signal which, however, disappears immediately upon cell disruption. Examination of the properties of this extremely low field signal revealed that it...

Multiplexing, labeling for multiple immunostains in the very same cell or tissue section in situ, has raised considerable interest. The methods proposed include the use of labeled primary antibodies, spectral separation of fluorochromes, bleaching of the fluorophores or chromogens, blocking of previous antibody layers, all in various combinations. The major obstacles to the diffusion of this te...

A simple and rapid method for the assay of superoxide dismutase in biological samples is described. Present method takes advantage of the inhibition of NADH-dependent-nitroblue tetrazolium reduction by the dismutase. Inhibition of the chromogen formation by superoxide dismutase was linear with increase in enzyme concentrations. The chromogen extract in butanol was stable even up to 48 hr. Super...

In connection with other studies in this laboratory (1, 2),’ it became necessary to determine the concentration of urea in the blood of individual new-born rats. In view of the small quantities of blood available and the need for a considerable number of analyses, the calorimetric method developed by Archibald (3) appeared to be particularly suitable. This method is based upon the formation of ...