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Biomedical subjects

B K van Weemen

Publications and source records attributed to B K van Weemen.

9 recordsLinked to original sources
PubMed1980

Enzyme-immunoassay: a powerful analytical tool.

This paper reviews various aspects of enzyme-immunoassay (EIA). Firstly it summarizes the principles of tests in which use is made of labelled antigen or antibody. Since these constitute essential reagents in EIA they are discussed next. Many assay principles call for a bound/free separation. The various methods to accomplish this are therefore briefly discussed. Very important are the characteristics of EIA: specificity, sensitivity, precision and practicability, the latter including reagent stability, performance requirements, assay times and automation potential. Finally, fields of application are listed and some more recent developments are mentioned.

Agglutination↗
PubMed1978

Enzyme immunoassay for total oestrogens in pregnancy plasma or serum.

We have developed an enzyme immunoassay for total oestrogens in pregnancy serum of plasma, using horseradish peroxidase (HRP) as the marker enzyme. A test combination consisting of an antiserum against oestriol-16/17-monosuccinyl-albumin and oestriol-16/17-monosuccinyl-HRP yielded a sensitive system, which reacted to approximately the same extent with oestrone, oestradiol, oestriol and their 16- and 17-conjugates. Samples had to be diluted 1 to 10 to avoid interference of plasma factors with the immune reaction. Bound/free separation was achieved with the double antibody solid phase (DASP) method. The HRP activity of the bound fraction was measured, after washing, to eliminate plasma factors disturbing the HRP reaction. The detection limit of the assay system was approx. 0.1 pmol/tube, while the index of precision lambda ranged from 0.02 to 0.06. To measure total oestrogens, including the 3-conjugated ones, we used an enzymatic hydrolysis with an extract of Helix pomatia. Hydrolysis was found to be optimal after 1 h at 50 degrees C and pH 5.0. The method was used on serum samples from normal pregnancies. The results showed a very good correlation (r=0.98) with those obtained by radioimmunoassay. Normal values for total oestrogens during pregnancy were determined in a multicentre clinical trial.

Antibody Specificity↗
PubMed1978

A simple and efficient method for raising steroid antibodies in rabbits.

The production of estradiol antibodies by two immunization procedures was monitored by means of an enzyme-immunoassay. Procedure A consisted of three intramuscular injections given at two-week intervals, followed by five intravenous booster injections and procedure B consisted of multiple intradermal injections given once. Procedure A gave much higher antibody titer. In both procedures the sensitivities of assays using the antisera increased initially and reached a plateau after three to four months of immunization. Consistent changes in specificities were observed. A shortened procedure A is proposed as a simple and efficient procedure for raising steroid antibodies in rabbits.

Animals↗