Abstract
It has been previously reported that OMK reaction which is based on the specific tuberculosis hemagglutination reaction established by Middlebrook-Dubos is available for the determination of tuberculinlike substance in urine.
In this experiment, the determination of low-concentration tuberculin by hemagglutination was studied for a basis of OMK reaction.
The agglutination of human O-type erythrocytes sensitized with low-concentration old tuberculin (OT) was examined by goat sera which reached to the high titer of 1:20, 480 in Middlbrook-Dubos' reaction.
By the use of hole-glass m ethod which was previously reported, there ob served not so constant reappearance. This irregularity of the reappearance was likely due to the individuality of erythrocytes in the response to sensitization with OT, or due to the difficulty in the reading of endpoint, which derived from a “stick” phenomenon, namely a sticking of erythrocytes to the bottom of hole.
By the addition of casein in a concentration of 0.01 per cent to the dilution medium (isotonic phosphate buffer) of antisera, the “stick” phenomenon was completely prevented, and became possible to read the endpoint very distinctly. Consequently, the constant reappearance of reaction became to be observed. Therefore, the individual difference in erythrocytes might not be considered.
The sensitivity of erythrocytes to tuberculin also was increased by diminishing their mixing rate to OT solution.
