[Determination of the immunoglobulin G supply in the newborn calf]. / Bestimmung der Immunglobulin-G-Versorgung beim neugeborenen Kalb.

A sufficient supply of colostral antibodies within the first hours of life is crucial for the development and the health status in young calves. It is rational to examine the immunoglobulin uptake of single animals, but particularly on a herd basis, during herd controls and consultations. This enables economical calf rearing in accordance with animal welfare. Because of the costly, laboratory-dependent and in part time-consuming direct measurement of the absorbed immunoglobulins using radial immunodiffusion (RID) or ELISA, multiple studies attempted to develop indirect methods, which would be affordable and operational in the field. These aim to draw an inference for the absorbed quantity of colostral antibodies based on other correlated parameters. Multiple validations showed in part significant differences between various methods concerning specificity and sensitivity in comparison to the direct methods. In addition to RID and ELISA, this article presents the measurement of the γ-glutamyltransferase (GGT) activity, the determination of the total serum protein concentration using refractometry and the zinc sulphate turbidity test, and describes the advantages and disadvantages of their application. Refractory measurement and determination of the GGT activity represent a valuable alternative to a laboratory-dependent immunoglobulin G measurement. Nevertheless, there is no ideal rapid test method, such that several influencing factors have to be considered.

Immunoelectrophoresis: A Method with Many Faces.

Immunoelectrophoresis (IEP) was the first practical method that combined electrophoresis and immunoprecipitation for identifying and characterizing proteins within complex mixtures. Over the years, IEP has been extended to include a variety of techniques and, as a general name, has been applied to virtually any technique that involves electrophoresis and antigen-antibody precipitin reaction for proteins. Because of the diversity in technical details of different IEP versions, the method described here deals only with classic IEP. Although it requires some manual expertise, IEP is versatile, relatively easy to customize, and economical with no need for expensive instrumentation. Further, it can discern identity, partial identity, and nonidentity of the proteins. Any low-viscosity body fluid specimen or, possibly, culture fluid and tissue extract could be tested with IEP if proper antibodies are available. With these attributes, classic IEP remains a valuable tool for clinical diagnostic testing, purity checking of biochemical and pharmaceutical products, and research.

Apoprotein assays: radial immunodiffusion versus an immunoturbidometric technique.

The measurement of apolipoprotein using radial immunodiffusion (RID) and Cobas-Bio immunoturbidometric assays is compared. Samples were obtained from 100 patients in a fiber-diet study. RID assays were performed using plates, standards, and diluent from Tago Inc. The immunonephelometric assays were performed on a Cobas-Bio with DENS program centrifugal analyzer. The correlation coefficient for the apolipoprotein Al was 0.90 and for apolipoprotein B was 0.91. The bias of the RID was to report higher values. The Cobas-Bio system affords the clinical laboratory with a reliable and cost-effective means for assessing these apolipoproteins.

[An economical modification of radial immunodiffusion for the determination of immunoglobulins in the cerebrospinal fluid]. / Eine ökonomische Modifikation der radialen Immundiffusion zur Bestimmung von Immunglobulinen im Liquor cerebrospinalis.

In a total of fifty cerebrospinal fluids, such immunoglobulins as IgG, IgA, and IgM were quantitatively determined in a parallel manner on LC partigen plates and on slides (SEVAC set of means of testing). The comparability of the two methods of test proved excellent with good precision. The sensitivity of IgA determination on slides was made higher, the measurability of all precipitates was improved, and the economic advantage increased by cutting the cost of one determination fifteen times.