Extraction of nucleic acids from bacterial spores using bead-based mechanical lysis on a plastic chip

This paper describes an experimentally simple and efficient way of integrating bead-based mechanical cell lysis on a plastic chip. The chip is fabricated from machined slides of poly(methylmethacrylate) and accommodates a metal disk along with solid microbeads in a designated lysis chamber. Magnetic actuation of the metal disk induces collisions and frictional forces within the lysis matrix causing cell disruption. The efficiency of nucleic acid extraction was investigated using spores of Bacillus atrophaeus subsp. globigii and the amount of genomic DNA in the lysates has been quantified by real-time PCR. Compared to a standardized DNA extraction method based on BD GeneOhm (TM) Lysis Kit, the yield was dependent on the composition of the lysis matrix, including size and relative amount of microbeads, along with instrumental parameters, such as duration and frequency of agitation. The interplay of these parameters should allow for optimizing lysis protocols to faithfully disrupt any particular type of cell without affecting the genetic material to be extracted.