Division 3 Addition of antigen:F1F2

petri dishes 1 and 3:

1. (i)

   well A — undiluted reference antigen;

2. (ii)

   well B — 1:2 diluted reference antigen;

3. (iii)

   wells C and E — reference antigen;

4. (iv)

   well D — undiluted test antigen;

petri dishes 2 and 4:

1. (i)

   well A — undiluted test antigen;

2. (ii)

   well B — 1:2 diluted test antigen;

3. (iii)

   well C — 1:4 diluted test antigen;

4. (iv)

   well D — 1:8 diluted test antigen.