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M H Hatch

Publications and source records attributed to M H Hatch.

52 records · Page 3Linked to original sources

Interactions of standard antibody with Australia antigens in Au Ag-Ab radioimmunoassay.

Human antisera against Australia (Au) antigen have been characterized by liquid-phase radioimmunoassay (RIA) for their precipitation of (125)I-labeled Au antigen. The end-point dilutions of sera (anti-Au) which precipitated 50% of (125)I-Au antigen by RIA correlated well with complement fixation titers but had a much wider range, indicating a greater precision and perhaps a better sensitivity of assay. Anti-Au serum diluted to precipitate 50% of (125)I-labeled Au antigen was used as standard antibody in RIA tests to detect either inhibition or enhancement of the reaction by preincubated mixtures of Au antigen and antibody specimens. Without free Au antigen or antibody in the resultant mixtures there was no inhibition or enhancement; the mixtures presumably contained immunoreactively equivalent proportions of Au antigen and antibody. RIA data for diagnostic specimens indicated an end-point sensitivity which was proportional to the dilution of the standard anti-Au sera used in the test. High concentrations of the standard antibody permitted detectable inhibition of (125)I-Au antigen precipitation at lower antigen specimen concentrations. Similarly, low concentrations of the standard antibody permitted detectable enhancement of (125)I-Au antigen precipitation at lower antibody specimen concentrations. Omitting the standard antibody altogether resulted in a more sensitive RIA for Au antibody in test sera.

Antibodies, Viral↗

Fluorescent-antibody studies with antisera against heated and unheated poliovirus type 1.

Fluorescent-antibody (FA) reagents were prepared from sera of guinea pigs immunized with either native infectious poliovirus type 1 or poliovirus type 1 which had been heated at 56 C for 30 min. Conjugates made from sera of animals immunized with heated virus gave higher direct FA staining titers on air-dried, acetone-fixed, infected cells than conjugates made from sera of animals immunized with native infectious virus. Evidence was obtained that complement-fixing antibody reactive with heated antigen was responsible for the FA staining. Two conjugates prepared from sera of guinea pigs immunized with heated poliovirus type 1 were successfully used to identify 21 type 1 viruses isolated from a group of 44 stool suspensions studied as unknowns. These conjugates did not stain any of 23 heterologous enteroviruses present in the remainder of the stools and gave minimal non-specific staining.

Animals↗

A comparative study of agar overlay and standard tissue culture methods for isolation of enteroviruses.

A study was made of the isolation of enteroviruses from 62 cerebrospinal fluids and 141 autopsy specimens with standard fluid monolayer tissue culture methods and tissue cultures under agar overlay with and without added MgCl2 (0.025M). Sixteen virus isolations were made only by the overlay method, two only by the standard technique, and six by both procedures. Additional studies were carried out on 975 diagnostic specimens of various types with standard tissue culture methods and with primary rhesus kidney cells under agar overlay containing 0.025M MgCl2. Seventeen virus isolations were made only by the overlay procedure, 20 only by the standard tissue culture method, and 75 by both techniques. Since there were instances in which either the agar overlay or the standard method alone succeeded in isolating a virus, use of both types of procedures would be desirable to isolate as many enteroviruses as possible from clinical specimens.

Agar↗