Inventors:
Thomas M. Daniel - Shaker Heights OH
International Classification:
A23J 106
Abstract:
The subject invention is directed in general to a method of preparing an antigen using immunoabsorbent affinity chromotography particularly in cases where an antigen is used for the recognition and measurement of hypersensitivity and where antigenic specificity is desired as, for example, in hypersensitivity to tuberculin, histoplasmin, coccidioidin, and common inhalant allergens. More particularly, this invention consists of a method which includes the following steps: immunizing a suitable host animal, usually a goat, with a preparation containing the desired antigen, collecting antisera from the animal and selecting the most specific antisera; isolating the antibody containing gamma globulin from the selected antiserum; coupling the globulin to an inert substrate (usually agarose beads) by chemical bonding with cyanogen bromide to form an absorbent in which the antibody acts as ligand; using the absorbent to bind selectively the desired antigen in a crude mixture containing the antigen; eluting the antigen from the absorbent by breaking the antigen-antibody bond with urea, usually at 4 - 6 molar (also referred to as M in the specification) and about pH 7 - 9; and then recovering the eluted antigen and preparing it in a form suitable for its intended use. By this method a highly purified, improved tuberculin skin test reactant is produced from culture filtrate which is prepared by growing tubercle bacilli in a liquid, synthetic medium, collecting and sterilizing by filtration the liquid phase of this culture (alternatively a soluble extract of the bacillary mass may be used), and then processing this filtrate and purifying the antigen by the steps described.