Rapid Regeneration and Reuse of Silica Columns from PCR Purification and Gel Extraction Kits

Abstract

Silica columns from PCR purification and gel extraction kits are widely used in laboratories worldwide to assist in gene cloning. However, the use of these columns can generate plastic waste that has an environmental impact due to their one-off design and massive consumption. Thus, it is important to develop a novel method that can reduce the utilization of silica columns but not affect research efficiency. In this study, various chemical and nonchemical reagents were used to eliminate residual DNA within used columns from PCR purification and gel extraction kits. We show that phosphoric acid is the most effective reagent among those tested to remove DNA contamination from used columns. Columns regenerated using 1 M phosphoric acid have a DNA purification capability that is comparable to that of fresh columns. We demonstrate that silica columns can be regenerated and reused a minimum of five times. The lab-made buffers are compatible with the regenerated columns for DNA purification, and DNA that is prepared with the regenerated columns can be used for gene cloning without affecting the gene cloning efficiency. Thus, the use of this novel method greatly reduces the production of laboratory waste and benefits numerous laboratories worldwide.