A linear relationship exists between the logarithm of the quantity of epidemic influenza virus neutralized and the logarithm of the quantity of antiserum which is capable of achieving this result. This relationship is the same for the serum of a ferret convalescent from experimental influenza as for the serum of a rabbit immunized with the virus. By means of the linear relationship between viru...

Measurements indicate that bacterial antigens increase in volume as the result of specific agglutination. There is a general parallelism between the increase in antigenic volume and the concentration of the immune serum. The phenomenon is specific. There is no increase with normal serum; with absorbed serum the increase is slight and it can be correlated with the presence of unabsorbed antibody...

Hemoglobin contamination in antiserum occurs frequently in immunohematology. The hemoglobin obscures the ring test for the observation of antigen-antibody reaction. A simple method to remove hemoglobin from antiserum is described in this paper. An appropriate amount of CM-Sephadex was added to antiserum containing hemoglobin and the mixture was packed into a cellulose tube, followed by dialysin...

Mouse thymus cells, educated to poly(tyrosyl,glutamyl)-polyDLalanyl--polylysyl [(T,G)-A--L], release an antigen-specific factor on brief culture in vitro. The factor cooperates with bone marrow cells in the antibody response to (T,G)-A--L in irradiated recipients. Its mol wt determined from Sephadex G100 chromatography is in the region of 50,000. The factor is removed by specific antigen-coated...

Of 91 compact-type strains of Staphylococcus aureus in regular serum soft agar (SSA), 82 converted diffuse-type growth in serum soft agar (pH adjusted to 6.0). With the addition of four different rabbit anticapsular sera (anti-type A, B, C, and D sera) in low pH (6.0) SSA, 21 strains of S. aureus showed compact-type colonial morphologies. Eleven, one, and one strains of S. aureus reacted singly...

Further mapping of the mouse T-cell factor specific for poly(Try,Glu)-polyD-LAla--polyLys is reported. It is shown to be a product of the I-A subregion of the H-2 complex by the use of antisera either raised specifically against or made specific, by absorption, for different regions of the H-2 complex. The factor cooperates across allogeneic barriers, e.g., when factor produced by one strian is...