Table 3

Positive SV40 DNA results in laboratory-prepared positive (two replicate samples for each titration) and negative (five replicate samples each) controls

LaboratoryAssayPositive control specimens (two samples each) No. of SV40 genome copies containedNegative control specimens (5 samples each per batch)
50,0005000500505Batch 1aBatch 2
Lab 1Common2222252
Lab 2Common2222130
Assay 2.12222150
Lab 3Common2222252
Assay 3.12220000
Assay 3.22212100
Lab 4Common1 of 1b222220
Lab 5Common2212140
Assay 5.12212040
Assay 5.22212040
Lab 6Common2200000
Lab 7Common2222250
Assay 7.12222250
Lab 8Common2221250
Assay 8.12210120
Lab 9Southern0100111
  • a Batch 1 was contaminated with SV40 when samples were aliquoted (see text). Batch 2 was prepared separately ∼1 month later.

  • b The amplicon from one sample was lost and could not be tested.