Abstract: The present invention relates to a process for determining the complement-dependent cytotoxicity mediated by anti-HLA antibodies wherein the cytotoxicity is determined by measuring the loss of intracellular ATP after addition of complement to anti-HLA coated target cells. the invention also relates to an automatical device for ATP determination.

Abstract: There is provided a process for extraction of a microorganism, which comprises treating said microorganism with a 4 to 8 molar aqueous solution of a guanidine salt, subsequently washing it to liberate it from the salt and thus obtaining it and diagnostic agents containing a microorganism so extracted.

Abstract: A method is provided for sampling and measuring the content of a low-molecular weight compound, such as glucose, cholesterol, or urea, in a complex fluid medium to be sampled, such as blood. A dialyzer is placed in contact with the complex fluid medium so that it passes through the dialyzer. One or more semipermeable membranes are disposed within the complex fluid medium to form one or more passageways for the passage of dialysis fluid, with the passageways being substantially smaller in volume than the volume of the surrounding complex fluid medium. A fractional portion of the complex fluid medium is acted on by the dialysis fluid and dialyzed so that only a fractional portion of the low-molecular weight compound diffuses into the passageways containing the dialysis fluid to produce a dialysate in the passageways. The dialysate is then measured to determine the content of the low-molecular weight compound in the complex fluid medium.

Abstract: A diagnostic method is disclosed, based on the automated kinetic determination of LDH and MDH isoenzymes in serum, which utilizes the comparison of two rates of LDH and MDH activity at different concentrations of substrate. A step is eliminated from the procedure previously proposed, significantly improving the method. The method is based on the principle that the pure and hybrid forms of LDH and MDH isoenzymes differ in their affinities for and are inhibited to different extends by their substrate.

Abstract: Fructose productivity and isomerase activity in immobilized beds or column operations employing isomerases obtained from Bacillus organisms are significantly improved by isomerizing a high solids feed syrup at pH 7.0-7.5 and 55.degree. C. to 60.degree. C. Without adding cobalt to the feed streams, continuous column operation in excess of 4,000 hours and yielding greater than 3,500 pounds of a 42% fructose syrup for each pound of isomerase can be achieved.

Abstract: A novel composition is disclosed for determining the activity of the alkaline phosphatase, which comprises a salt of p-nitrophenylphosphoric acid, a magnesium salt, sodium borate and 2-amino-2-hydroxymethyl-1,3-propanediol. The composition affords advantages over the known composition especially as regards sensitivity.

Abstract: Microbial cells having active enzymes associated therewith are subjected to flocculation conditions to produce a flocculated whole cell aggregate that is useful in effecting enzyme-catalyzed chemical transformations. Substrates are brought into contact with the flocculated cell aggregates where they undergo chemical transformations in the presence of active enzymes associated with the cells.