EVALUATION OF AUTOMATED DNA PURIFICATION BY THE GenoMJ-48.
C Newman1, C Avergas1, RAP Stacy2, MS Leffell1, AA Zachary1 1 Dept. Medicine, Johns Hopkins U., Baltimore, MD, 2 GenoVision Cytomics, Oslo, Norway

We performed 234 automated DNA extractions on specimens from 75 individuals consisting of 20 healthy controls, 41 organ transplant candidates (OTC), and 14 hematology patients. Parallel DNA extraction using QIAamp7 Blood Mini Kit was performed on 71 specimens. All the DNA extracts were evaluated by spectrophotometry for purity and yield, and for quality assessed by one or more typing methods - SSP, in-line reverse hybridization, and/or SBT. Replicate testing was performed to evaluate within and between run reproducibility. Purity of the automated DNA extracts (aDNA) was significantly (P<10-6) better than that of extracts obtained manually (mDNA), with 260:280 ratios of 1.78+0.007 vs. 1.71+0.047, respectively. The yield concentrations were 30.3 vs. 74.1?g/ml (aDNA vs mDNA, P<10-9). Yield did not vary among the controls, OTC, and hematology patients (30.3, 30.8, 29.2?g/ml, respectively). Successful typings were obtained with all aDNA extracts, by all typing methods, and there were no disparities between results of tests on aDNA vs mDNA. There was no significant variability in yield either within or between runs. There were significant differences in purity which was greater between runs (1.79 vs 1.74, P<10-8) than within run (1.79 vs. 1.78, P=0.01). The instrument can extract DNA or RNA from up to 48 specimens simultaneously, with run times of 15 min.(6 samples) - 2 hrs. (48 samples). The instrument is equipped with a cooling block to permit overnight runs. An internal UV lamp and drop catcher tray provide a safe pre-amplification environment, while HEPA filtration assures personnel safety. In tests of 3 samples using different starting volumes, efficiency of yield decreased as starting volumes increased from 25-100?l. In summary, we have found that the GenoM-48 provides a hands free, automated DNA extraction with a yield comparable in purity and quality to manual methods. Evaluation of improved yield protocols and assessment of personnel time saved is underway.