Biomedical subjects

J Kühner

Publications and source records attributed to J Kühner.

2 recordsLinked to original sources

PubMed1978

[Experiences with an enzyme-immunoassay for hepatitis B antigen detection in blood donors (author's transl)].

In a comparative study 12,080 sera from unpaid donors were tested simultaneously for Hepatitis B Antigen (HBsAg) by enzyme-immunoassay (EIA) and radioimmunoassay (RIA). A relatively high number of sera reacted positive in the EIA-secreening test but were negative after repeated investigation. This percentage could be markedly reduced when using an automated washing apparatus. After neutralization 0.31 per cent were considered as true positive in EIA and RIA, thus demonstrating that no differences did exist as far as sensitivity is concerned. The EIA needs more incubation time than the RIA, however, the EIA has the advantage of using enzyme-labelled antibodies instead of radio-iodinated reagents. The results are read immediately and no sophisticated equipment is required. The EIA is easy to handle, two technicians can perform 1000 tests per day.

Blood Donors↗

PubMed1976

Fluorogenic substrate turnover in single living cells.

Intracellular diffusion properties and enzyme activities in single living cells can be analysed by means of fluorogenic substrates that diffuse into the cells where they are converted into a fluorescent product by an enzymic reaction. The reaction-kinetic analysis of this process as a system of consecutive reactions provides information on the diffusion of the substrate into the cells, on intracellular enzyme activities and on the efflux of the fluorescent product. Separation of diffusion and enzyme-mediated processes is obtained by inducing specific changes of the cellular membrane using gramicidin D. A model for the functional interpretation of the experimental findings is proposed. Application of this method as a viability test for freshly prepared and frozen platelets is discussed.

Blood Platelets↗