[White paper] Best practices for DNA sample preparation with Precellys homogenizers

DNA extraction is a method to purify DNA by using physical and/or chemical methods from a sample, separating DNA from cell membranes, proteins, and other cellular components. A large number of techniques have been developed since the first DNA extraction was carried out by Friedrich Miescher in 1869. Nonetheless, there are five basic steps of DNA extraction that are consistent across all the possible DNA purification chemistries: 1) cellular lyses, 2) separation of the soluble DNA from cell debris, 3) binding the DNA of interest to a purification matrix, 4) washing proteins and other contaminants away from the matrix and 5) elution of the DNA.

With today’s requirements for DNA analyses by multiplex, real-time PCR and NGS, the importance of high-quality, purified DNA cannot be underestimated. Various factors, such as tissue type and DNA integrity, must be considered for choosing the appropriate DNA extraction method. Precellys homogenizers play a key role at the beginning of all the workflows requiring a biological sample homogenization for molecule extraction as a first step. In this White Paper, we have listed some tips and tricks, as well as some case studies of how to use your Precellys homogenizer to optimize the separation of the soluble DNA from your samples.

TIPS & TRICKS FOR DNA SAMPLE PREPARATION

• Make sure that your work surfaces and tools are free of Dnases.
• Pre-cut your samples into smaller pieces, if possible.
• Maintain your samples on ice as much as possible or use Bertin Cryolys cooling systems.
• Use a lysis buffer during the homogenization step in order to increase the yield of DNA. Make sure that the lysis buffer of your choice is compatible with your downstream application.
• Make sure that you have selected the optimal lysing kit and homogenization protocol for your sample type.
• Keep your homogenization cycles short. Give priority to increasing the number of cycles or speed, rather than the duration of each cycle.
• Centrifuge your samples at maximum speed for a few seconds after homogenization. This will facilitate the pipetting of the homogenate (without beads) to a clean tube for your downstream application.