(1) Sample collection shall be done in accordance with guidelines and instructions provided by official veterinarians.

(2) An official veterinarian shall determine a minimum sample requirement for the primary testing laboratory.

(a) If the specimen obtained from a horse is less than the minimum sample requirement, the entire specimen shall be sent to the primary testing laboratory.

(b) If a specimen obtained is greater than the minimum sample requirement but less than twice that amount, the portion of the sample that is greater than the minimum sample requirement shall be secured as the split sample.

(c) If a specimen obtained is greater than twice the minimum sample requirement, a portion of the sample approximately equal to the amount provided for the primary testing laboratory shall be secured as the split sample.

(d) Blood samples must be collected at a consistent time, preferably not later than one hour post-race.

(e) At Class C race tracks the splitting of samples will be conducted by the primary testing laboratory.