Evaluation of the effectiveness and safety of the thermo-treatment process to dispose of recombinant DNA waste from biological research laboratories.
The discharge of recombinant DNA waste from biological laboratories into the eco-system may be one of the pathways resulting in horizontal gene transfer or "gene pollution". Heating at 100 degrees C for 5-10 min is a common method for treating recombinant DNA waste in biological research laboratories in China. In this study, we evaluated the effectiveness and the safety of the thermo-treatment method in the disposal of recombinant DNA waste. Quantitative PCR, plasmid transformation and electrophoresis technology were used to evaluate the decay/denaturation efficiency during the thermo-treatment process of recombinant plasmid, pET-28b. Results showed that prolonging thermo-treatment time could improve decay efficiency of the plasmid, and its decay half-life was 2.7-4.0 min during the thermo-treatment at 100 degrees C. However, after 30 min of thermo-treatment some transforming activity remained. Higher ionic strength could protect recombinant plasmid from decay during the treatment process. These results indicate that thermo-treatment at 100 degrees C cannot decay and inactivate pET-28b completely. In addition, preliminary results showed that thermo-treated recombinant plasmids were not degraded completely in a short period when they were discharged into an aquatic environment. This implies that when thermo-treated recombinant DNAs are discharged into the eco-system, they may have enough time to re-nature and transform, thus resulting in gene diffusion.
State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China.
Meng-Nan
MN
Li
Guang-Hong
GH
Zheng
Lei
L
Wang
Wei
W
Xiao
Xiao-Hua
XH
Fu
Yi-Quan
YQ
Le
Da-Ming
DM
Ren
D002681:China; D004274:DNA, Recombinant / Q000302:isolation & purification* / Q000378:metabolism / Q000633:toxicity; D004586:Electrophoresis; D006361:Heating; D007753:Laboratories; D009994:Osmolar Concentration; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012106:Research; D017751:Safety Management / Q000379:methods*; D013997:Time Factors; D018505:Waste Management / Q000379:methods*
D004274:DNA, Recombinant