Abstract: Anti-hepatitis B virus surface protein (anti-HBS) antibody is adsorbed onto the surface of a substratum. Hepatitis B virus PreS2+S (PreS2+S) protein is then adsorbed onto the same surface through the interaction of the anti-HBS antibody with the "S" portion of the PreS2+S protein. The coated surface is then incubated concomitantly with the test sample and a radiolabelled antibody specific for the "PreS2" portion of the PreS2+S protein.

Abstract: A quantitative assay for HAV comprises infecting at a temperature of from about 30.degree. to about 37.degree. C. a cell sheet with a dilution series of hepatitis A virus and then adding Newcastle disease virus (NDV) to the infected cell sheet and incubating the infected cell sheet in the presence of NDV at an elevated temperature for a time sufficient to permit a cytopathic effect (CPE) to become manifest, this time typically being at least about 4 days and preferably about 5 days. At an incubation temperature of from about 31.degree. to about 33.degree. C. the absence of CPE indicates the presence of HAV and the presence of CPE indicates the absence of HAV. At an incubation temperature of from about 34.degree. to about 36.degree. C. the absence of CPE indicates the absence of HAV and the presence of CPE indicates the presence of HAV.

Abstract: A diagnostic reagent for hepatitis A antibody is prepared by adhering hepatitis A antibody to a surface by non-specific adsorption followed by specific coupling of hepatitis A antigen to the antibody. This reagent is useful in an in vitro assay for hepatitis A antibody.

Abstract: A method for determining the end point in a viral assay comprisingelectronically scanning a microtiter plate to obtain a plurality of data points from each well,transmitting the data points to a digital computer programed to analyze the data points from each well to determine whether each well is positive or negative for CPE in accordance with predetermined parameters, andcalculating the viral titer from the positive or negative results for each well.

Abstract: Liquid containing hepatitis A antibody is adsorbed on a surface. The surface is then coated with a proteinaceous material and incubated in the presence of the sample to form a complex of hepatitis A antigen and hepatitis A antibody. The complex is incubated again in the presence of excess radioactively labelled hepatitis A antibody, and the resulting radionuclide is measured.

Abstract: Automated means are provided to harvest virus at a time when the yield is optimized and store the harvest with minimum loss thereby eliminating difficulties when the optimum yield time does not fall within normal working hours, enhancing sterility by limiting human contact and enhancing stability of the product.

Abstract: It has now been found that small size particles may be extracted from a proteinaceous liquid at a low flow rate in flow-centrifuge operation by precooling the liquid before it enters the centrifuge and by employing a multi-step gradient.

Abstract: A method and apparatus for recovering embryos from embryonated eggs wherein the egg is cracked open the shell discarded and the contents dropped onto a continuously vibrating screen which separates the embryo from the yolk sac and accompanying fluid. This associated material, which is less cohesive than the embryo, passes through the screen. The screen itself is tilted at a compound angle from the horizontal and its vibrating action causes the embryos to move along the upper surface of the screen toward a discharge chute located at the lower corner of the screen.

Abstract: Apparatus and method for automatically reading a microtiter plate comprises a light source, a photo sensor, means enabling the photo sensor to measure light transmittance and means for recording and processing the measurements.

Abstract: A method and apparatus for recovering embryos from embryonated eggs wherein the egg is cracked open the shell discarded and the contents dropped onto a continuously vibrating screen which separates the embryo from the yolk sac and accompanying fluid. This associated material, which is less cohesive than the embryo, passes through the screen. The screen itself is tilted at a compound angle from the horizontal and its vibrating action causes the embryos to move along the upper surface of the screen toward a discharge chute located at the lower corner of the screen.

Abstract: Apparatus for physically removing cells in a sterile manner from a disc stack on which the cells have been cultured comprises a substantially shaft-like member having at least one butressed rod-like member mounted at substantially a right angle to the axis of the rod.

Abstract: An apparatus and a method for preparing live, sterile cells from tissue are disclosed which enable high yields of viable isolated cells to be obtained with a greatly reduced possibility of contamination of the cells during the process. The apparatus and method allows one to truly mass manufacture isolated cells as contrasted to a small hand operation requiring many hours and dozens of people. The improved apparatus of the invention comprises a shredder device which mechanically shreds the tissue into small pieces of high surface to volume ratio, a processing vessel in which the shredded tissues are contacted with an enzyme solution to break down the intercellular material and thereby separate the cells one from the other and a means for separating the cells from the enzyme solution. Preferably, the means for separating the cells from the enzyme solution is a flow centrifuge which has been specifically designed to reduce shear force inside the bowl during operation.

Abstract: Apparatus for physically removing cells in sterile manner from a disc stack on which the cells have been cultured comprises a substantially shaft-like member having at least one rod-like member mounted at substantially a right angle to the axis of the shaft.