Abstract: There is disclosed a filter comprising fibrin in gel form, the gel having substantially uniform pore sizes, and the filter comprising means for retaining the shape of at least one surface of the gel against deformation when contacted by a flowing medium.

Abstract: A process for detecting the presence of an antigen in a specimen is described, which process comprises:(A) contacting said specimen with a substrate coated with antibodies of said antigen, incubating the contacted substrate and washing the substrate;(B) contacting the washed material of step (A) with a hapten conjugated antibody against said antigen, incubating the so-contacted material and washing the so-incubated material;(C) contacting the washed material of step (B) with a radioactive material labeled or enzyme containing anti-hapten antibody, incubating the so-contacted material and washing the same; and(D) effecting radioimmunoassay if said antibody is radioactive or enzyme labeled immunoassay if said antibody contains an enzyme moiety.Quantitative determination of the antigen in the specimen is effected by comparing the counts of the radioimmunoassay or the concentration of enzyme against a standard as by photocolormetric methods.

Abstract: A process for the detection of an antigen or antibody in a specimen which process comprises:(a) contacting said specimen with a substrate having bound thereon a mixture of antigens and antibodies to said antigen or antibody in said specimen, said antibodies and said antigens bound to said substrate being separately bound to said substrate and not in the form of an immune complex, incubating the so-contacted substrate and washing the substrate;(b) contacting the washed material of step `a` with a radioactive material labeled or enzyme labeled antibody or antigen, incubating the so-contacted material and washing the same; and(c) effecting radioimmunoassay if said antibody or antigen is radioactive or enzyme labeled immunoassay is said antibody or antigen is enzyme labeled.

Abstract: A mammalian blood plasma or plasma derivative substantially free of active hepatitis B or non-A, non-B viruses is disclosed, the plasma being characterized by the presence of factor VIII, the percent by weight of denatured factor VIII to the sum of undenatured factor VIII and denatured factor VIII being less than 50%. The plasma is sterilized by contact with a detergent, alcohol or ether, preferably a mixture of detergent and ether, usually followed by removal of the viral sterilizing agent.

Abstract: A process for determining the presence of an antigen or antibody in a sample wherein said antigen or antibody exists in the form of an immune complex which comprises:A. contacting the immune complex originating from the sample suspected of containing immune complex with a dissociating buffer whereby said immune complex, if present, is dissociated into antigen and antibody;B. contacting a solid support which binds proteins with said dissociating buffer suspected of containing antigen or antibody and removing said buffer;C. washing said solid support;D. adding protein to fill unoccupied sites on said solid support;E. adding radioactively labeled or enzyme labeled antibody or antigen to said solid support, said labeled antibody or antigen corresponding to antigen or antibody on said solid support, incubating the resultant mass and washing the same;F. measuring the radioactivity or enzymatic activity associated with the solid support.

Abstract: Transfusable type O erythrocytes free of P1 antigenicity which are produced by an alpha-galactosidase conversion of type B antigen to type H antigen. The resulting erythrocytes retain a high level of ATP and 2,3 DPG.

Abstract: A composition comprising type O erythrocyte free of P.sub.1 antigenicity; a method of converting erythrocytes of the B antigen type to erythrocytes of the H-antigen type which comprises:A. equilibrating said erythrocytes to a pH of 5.7-5.8;B. thereafter contacting the so-equilibrated erythrocytes with an enzyme for a period sufficient to convert the B antigen in said erythrocytes to the H-antigen;C. thereafter removing said enzyme from said erythrocytes andD. re-equilibrating said erythrocytes to a pH of 7.2-7.4.The specification discloses conversion of the B antigens in human and animal blood to the H antigen (O cells).

Abstract: A vaccine against viral hepatitis comprising:A. antigenic particles having a particle size in the range of 30 to 50 nanometers, said antigenic particles containing hepatitis B surface antigens;B. said antigen having less than 10 units of free antibody to hepatitis B surface antigens per 1,000 units of hepatitis B surface antigens;C. at least 5% of the particles of said vaccine in the size range of 30 to 50 nanometers containing the hepatitis B surface antigenic specificity(s) which have been termed "e-antigen";D. said hepatitis B surface antigens, including e-antigens, being present in said vaccine in an amount sufficient to produce antibodies when introduced into a host animal, the balance being a medium which is physiologically acceptable, especially to humans and primates.

Abstract: A process for preparing a vaccine containing unprecipitated filaments and hepatitis B Dane particle specific antigens by removal from a blood serum of other proteinaceous matter such that the serum contains less than 10% proteinaceous matter other than that associated with hepatitis B surface antigen or the filament or Dane particle specific antigen. Any virus present is inactivated, and the antigenous mass is diluted with a physiologically acceptable medium.

Abstract: A vaccine against viral heptitis comprising:A. antigenic particles having a particle size in the range of 30 to 50 nanometers, said antigenic particles containing heptitis B surface antigens;B. said antigen having less than 10 units of free antibody to heptitis B surface antigens per 1,000 units of hepatitis B surface antigens;C. at least 5% of the particles of said vaccine in the size range of 30 to 50 nanometers containing the hepatitis B surface antigenic specificity(s) which have been termed "e-antigen";D. said heptatis B surface antigens, including e-antigens, being present in said vaccine in an amount sufficient to produce antibodies when introduced into a host animal, the balance being a medium which is physiologically acceptable, especially to humans and primates.