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E Metzmann

Publications and source records attributed to E Metzmann.

6 recordsLinked to original sources
PubMed1988

New immunodiagnostic systems.

Two new systems for homogeneous plasma protein immunoassays, the Behring Nephelometer System and the Behring TurbiTimeSystem, as well as the Behring ELISA System for heterogeneous enzyme immunoassays are described.

Blood Proteins↗
PubMed1985

Protein quantitation on both branches of the Heidelberger curve by monitoring the kinetic of immunoprecipitation.

For every immunochemical protein quantitation, one must consider the ambiguity of concentration-dependent signals. In immunoprecipitation reactions, where such a phenomenon occurs, the problem has not yet been adequately addressed. Several methods have been cited, which claim to permit an exact concentration determination on the basis of two independent measurements. In the present paper a method is described, in which a concentration determination is unequivocally made through the simultaneous measurement of two (inter-related) reaction parameters. The maximum velocity (Vmax) of the immunoprecipitation and the time (tmax), which was required for the reaction to attain Vmax, are measured simultaneously. Specific test parameters are discussed for the routine protein quantifications. Based on the measurement of 83 samples with pathological immunoglobulins, the findings of this method are compared with those of the classical radial immunodiffusion.

Chemical Precipitation↗
PubMed1975

Influence of molecular weight of DNA on the determination of anti-DNA antibodies in systemic lupus erythematosus (SLE) sera by radioimmunoassay.

Using a radioimmunoassay (RIA) based on the Farr technique with radioactively labeled 3-H-DNA for quantitative measurements of anti-DNA antibodies in sera of patients with systemic lupus erythematosus (SLE), the influence of molecular weight of DNA (ranging from 0.1 times 10-6 to 22.0 times 10-6 daltons) on binding and precipitation in this system has been investigated. Comparing our results with mathematical models it follows that one antibody molecule is fixed on the average to a statistical DNA segment of 2 times 10-6 to 4 times 10-6 daltons. Furthermore binding capacity of the DNA was found to be independent of the molecular weight, as demonstrated in a double label experiment using 14-C and 3-H-labeled DNA of different size. However, the amount of radioactivity precipitated was found to depend on the molecular weight of the labeled DNA following a non-linear function. It was calculated that a minimal ratio of fixed antibody molecules per a certain size of DNA was necessary for precipitation. The mathematical treatment of the observed non-linear precipitation dependence will be discussed using various statistical models. Our results indicate that the quantitative measurements of anti-DNA antibodies with the Farr technique e.g. for diagnosis and control of SLE in clinical immunology is highly dependent on the molecular weight of the labeled DNA used in the assay system and reliable results are only obtained with DNA of a sufficiently high molecular weight.

Antibodies↗