Evaluation of the effectiveness and safety of the thermo-treatment process to dispose of recombinant DNA waste from biological research laboratories

• Published in: The Science of the total environment 2009, Vol.407 (2), p.791-797
• Main Authors: Li, Meng-Nan, Zheng, Guang-Hong, Wang, Lei, Xiao, Wei, Fu, Xiao-Hua, Le, Yi-Quan, Ren, Da-Ming
• Format: Article
• Language: English
• Subjects: Aquatic environment; Biological and medical sciences; Biotechnology; China; Decay/denaturation; DNA, Recombinant - isolation & purification; DNA, Recombinant - metabolism; DNA, Recombinant - toxicity; Electrophoresis; Environment and pollution; Fundamental and applied biological sciences. Psychology; Gene diffusion; Heating; Industrial applications and implications. Economical aspects; Laboratories; Miscellaneous; Osmolar Concentration; Plasmid DNA; Plasmids; Polymerase Chain Reaction; Safety Management - methods; Thermo-treatment; Time Factors; Transformation; Waste Management - methods
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2008.08.024

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 °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 °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 °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.