1. (a)

   a test serum is positive if it forms a specific precipitation line with the bovine leukosis virus (BLV) antigen and forms a complete line of identity with the control serum;

2. (b)

   a test serum is negative if it does not form a specific precipitation line with the BLV antigen and if it does not bend the line of the control serum;

3. (c)

   the reaction cannot be considered conclusive if it:

   1. (i)

      bends the line of the control serum towards the BLV antigen well without forming a visible precipitin line with the antigen; or

   2. (ii)

      if it cannot be read either as negative or as positive.

In inconclusive reactions the test may be repeated and concentrated serum utilised.