Table A.1

Total amount of DNA obtained from WI-38 cell preparations using Qiagen column purification versus phenol/chloroform extraction, based on spectrophotometry

SampleApproximate no. of WI-38 cellsExtraction methodAdded plasmid DNA (ng)Total DNA obtained (μg)
C1350,000Qiagen columnNone3.8a
C2350,000Qiagen column254.0
C3350,000Qiagen column504.0
P1700,000Phenol/chloroformNone2.0
P2700,000Phenol/chloroform502.5
P3700,000Phenol/chloroform1004.4
  • a The observed amount of DNA is greater than expected (∼2.6 μg) because the adherence of WI-38 cells leads to underestimation of the actual number of cells present. However, this applied equally to specimens processed by each DNA extraction method.