An enzyme linked immunosorbent assay for monitoring Bacillus sphaericus toxin.

Larvicidal proteins of B. sphaericus H5a5b (strain VCRC B42), purified by ion-exchange chromatography were used to raise antibodies in rabbits. The antibodies were specific in reacting to alkali-solubilized fractions from whole cells of toxic strains only. Ouchterlony immunodiffusion showed homology in toxin structure between strains of different serotype. A sandwich ELISA using avidin-biotin amplification was standardized. The lowest detectable limit was 6.25 ng/ml. Near linear quantitative binding of the antigen was found in the range 25-200 ng/ml. The growth, toxin level and LC50 values during various stages of fermentation of B. sphaericus strains 1593 and B42 were compared. There was significant correlation between LC50 values and toxin levels as measured by ELISA.

Evaluation of cyclosporine-A obtained from Tolypocladium sp. for immunosuppressive potential.

Cyclosporine-A obtained from an indigenous isolate of Tolypocladium sp. was evaluated for immunosuppressive potential by skin grafting in rats using the commercially available Sandimmune as reference at 15 and 30 mg/kg/day for a period of 14 days. The Sandimmune treated animal group showed 83 per cent acceptance of skin grafts while the test preparation treated group showed 67-83 per cent acceptance. The degree of nephro- and hepatotoxicity was comparable for both the preparations.