Animals were incorporated into pools in different proportions to estimate error and evaluate factors influencing error. Animals were incorporated into 2 types of pools, sub-pools and super pools. Within phenotype, liver abscess or normal, 16 animals were combined into 4 sub-pools, 4 animals per sub-pool in parts of 1:2:3:4. Sub-pools were constructed based on crushed frozen liver tissue mass. Within phenotype, 4 sub-pools were incorporated into 2 super pools in parts of 1:2:3:4 for super pool 1 and 3:4:1:2 for super pool 2. Super pools were made based on DNA quantity. Errors in DNA quantification would create error in forming super pools from sub-pools and variation in cell content or DNA content of liver tissue would result in error in combining sub-pools from animals.