Division Test serumX1

1 % agarose prepared in borate or sodium barbitol buffer, pH 8,5 to 9,0, is poured into a petri dish to a minimum depth of 3,0 mm. A test pattern of seven moisture-free wells, each 5,0 mm in diameter, is cut in the agar. The pattern consists of one centre well and six wells arranged round it in a circle of radius 3 cm. The central well is filled with the standard antigen. Peripheral wells 2, 4 and 6 are filled with known positive serum, wells 1, 3 and 5 are filled with test sera. The system is incubated for up to 72 hours at room temperature in a closed humid chamber.

A test serum is positive if it forms a specific precipitin line with the antigen and forms a complete line of identity with the control serum. A test serum is negative if it does not form a specific line with the antigen and it does not bend the line of the control serum. Petri dishes must be examined against a dark background and using indirect illumination.