[Quantitation of Acinetobacter calcoaceticus in mixed bacterial cultures by an enzyme immunoassay]. / Quantitative Bestimmung von Acinetobacter calcoaceticus in Bakteriengemischen mittels eines Enzymimmunassays.

An enzyme-linked immunosorbent assay using polyclonal antibodies from rabbits has been developed for quantification of Acinetobacter calcoaceticus. Bacteria were added to the wells of a microtiter plate coated with anti-Acinetobacter immunoglobulin. For detecting bound cells the peroxidase-labelled immunoglobulin fraction was used. Over a distinct range there is a linear correlation between bound bacteria and measured absorbance allowing a quantification of bacteria in an order from 10(7) to 10(8) per milliliter. The specificity of the assay was evaluated by the heterologous bacteria Pseudomonas putida, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli and Citrobacter freundii. Only a minimal cross-reactivity was observed. Within a certain range of error it is possible to quantitate Acinetobacter calcoaceticus in mixtures with one or several other bacterial species. Mixed with bacteria of one other species the differences to the value for Acinetobacter calcoaceticus alone do not exceed +/- 10% with a tendency to lower values. Mixed with several other species only negative differences up to -15% were obtained. Treatment of Acinetobacter calcoaceticus with 0.5% formaldehyde results in a loss of reactivity up to 15%. In conclusion, the enzyme-linked immunosorbent assay is a useful method for quantitating bacteria not only with respect to the high sensitivity, specificity and good reproducibility but also for the minimal technical equipment and the short assay time.

[Affinity chromatographic purification of streptokinase with monoclonal antibodies]. / Affinitätschromatographische Reinigung von Streptokinase mittels monoklonaler Antikörper.

Monoclonal antibodies against streptokinase as ligands were coupled to different matrices. Both CNBr-activated Sepharose and macroporous bead cellulose activated by carbonochloridate revealed as suitable for purification of streptokinase by affinity chromatography. Immunoadsorbents with a higher concentration of the coupled ligand were more effective than those with a lower. For streptokinase optimal conditions of binding and elution without negative influence on structure and activity were ascertained. A buffer with slight alkaline pH was successful for desorption. Using this method it was possible to obtain pure streptokinase from several streptokinase containing media.

Surface immunoglobulin on lymphocytes of the tortoise Agrionemys horsfieldii.

Surface immunoglobulin bearing (sIg+) cells were identified in the tortoise Agrionemys horsfieldii by indirect immunofluorescence by using class-specific antisera to tortoise IgM and IgY produced in mice. With this technique 13-23% of blood lymphocytes were found to bear surface IgM and 5-8% IgY. Spleen lymphocytes show a higher percentage of sIg+ cells: 25-52% sIgM+ and 5-20% sIgY+ lymphocytes. There is strong indication that tortoise sIgY+ lymphocytes of blood and spleen also express IgM on their surface.

[Structural and immunochemical studies of the immunoglobulins of carp (Cyprinus carpio L.) II. Analysis of the subunits]. / Strukturelle und immunchemische Untersuchungen am Immunglobulin des Karpfens (Cyprinus carpio L.) II. Analyse der Untereinheiten

The 14 S immunoglobulin of the carp (Cyprinus carpio L.) was split into subunits with 0,01 M dithioerythritol. These 5,7 S subunits have a molecular weight of 104 000 and a hexose and hexosamine content of 6.2%. It is likely that the subunits represent HL-half-molecules and not H2L2-monomeres. The values for the molecular of H- and L-chains were 77 000 and 24 000, respectively.