[Optimization of genomic DNA extraction with magnetic bead- based semi-automatic system].
OBJECTIVE
To develop a rapid and effective method for genomic DNA extraction with magnetic bead-based semi-automatic system.


METHODS
DNA was extracted from whole blood samples semi-automatically with nucleic acid automatic extraction system.The concentration and purity of samples was determined by UV-spectrophotometer. Orthogonal design was used to analyze the main effect of lysis time, blood volume, magnetic bead quantity and ethanol concentration on the DNA yield; also the 2-way interaction of these factors.


RESULTS
Lysis time, blood volume, magnetic bead quantity and ethanol concentration were associated with DNA yield (P<0.05), but no interaction existed. DNA yield was higher under the condition with 15 min of lysis time, 100 μl of blood volume, 80 μl of magnetic beads and 80 % of ethanol. A significant association was found between the magnetic bead quantity and DNA purity OD260/OD280 (P=0.008). Interaction of blood volume and lysis time also existed (P=0.013). DNA purity was better when the extracting condition was 40 μl of magnetic beads, 15 min of lysis time and 100 μl of blood volume. Magnetic beads and ethanol concentration were associated with DNA purity OD260/OD230 (P=0.017 and P<0.05), the result was better when magnetic beads was 40 μl and ethanol concentration was 80 %.


CONCLUSIONS
The results indicate that the optimized conditions with 40 μl magnetic beads will generate higher quality of genomic DNA from the whole blood samples.
Department of Epidemiology and Biostatistics, Zhejiang University School of Medicine, Hangzhou 31005, China.
Jie
J
Ling
Hao
H
Wang
Shuai
S
Zhang
Dan-dan
DD
Zhang
Mao-de
MD
Lai
Yi-min
YM
Zhu
D000704:Analysis of Variance; D004247:DNA / Q000097:blood / Q000302:isolation & purification*; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*
D004247:DNA