EasYeast - Yeast DNA extraction

As a general rule, EasYeast should work for all species with a cell wall mainly composed of peptidoglycan and/or glucans due to the physico-chemical properties of the lysis buffer (i.e. yeast, gram + bacteria). It seems to be less efficient with cell walls mainly composed of chitin (i.e. filamentous fungi).

So far, EasYeast has been successfully used to extract DNA from Saccharomyces cerevisiae, e.coli and Streptomyces. It may be used with other species, although the optimal temperature and/or duration of the lysis step might need to be adjusted. 

The EasYeast kits contain a Lysis buffer and a Stop buffer. All you need to provide on your side is some ultra-pure water (milliQ or molecular-grade), a centrifuge (ideally refrigerated, but a benchtop centrifuge will work too) and a way to heat-up the solutions at 45°C (thermocycler, water-bath or heating block). Some isopropanol may be needed if you wish to precipitate the DNA at the end of the protocol. 

Because the EasYeast solutions do not contain any SDS or phenol/chloroform, and the RNA gets mostly degraded upon lysis, a simple precipitation in isopropanol is sufficient to provide a functional DNA you can use directly for bacterial transformation using electroporation or PCR amplification. 

If ultra-pure DNA is required, an affinity-based purification can be performed instead of the alcohol precipitation. The EasYeast lysis and stop buffers are compatible with purification methods based on silica (i.e. NucleoSpin® from Macherey-Nagel or QIAprep Spin Miniprep Kit from Qiagen) and aluminium oxide membranes,   diatomaceous earth particles, carboxylated or silica magnetic beads, polymers (i.e. polyethyleneimine) or specialized chromatography resins (i.e. DEAE cellulose).

We do not recommend using the EasYeast kit for RNA isolation, as it will be mostly degraded by the lysis buffer components. This kit is primarily intended for DNA extraction.

Lots of home-made methods have been developed, that are also quick, cheap and easily scalable. In comparison, the EasYeast method was designed to better preserve the integrity of the extracted DNA: it does not use any SDS, and incubation temperatures do not exceed 45°C. As DNA is less fragmented at 45 °C, you can recover high-quality nucleic acids for downstream applications and get functional plasmids for bacterial transformation. The absence of SDS also minimizes the risk of interference with PCR or spectrophotometric DNA quantification. And of course, we know time is precious: with EasYeast, you'll have all solutions ready-to-use instead of having to make all of them every time. 

So far, DNA extracted using EasYeast has mostly been used for PCR amplification and bacterial transformation. That being said, the protocol is easily adjustable according to your needs: 

• if RNA-free genomic DNA is needed, RNase A can be added to the lysis buffer before adding the yeast. 
• the number of cells used for DNA extraction can be scaled up according to the desired yield of DNA, as long as the recommanded ratio between cells and lysis buffer is maintained.
• if ultra-pure DNA is needed, an affinity-based purification can be performed instead of the alcohol precipitation. The EasYeast lysis and stop buffers are compatible with purification methods based on silica (i.e. NucleoSpin® from Macherey-Nagel or QIAprep Spin Miniprep Kit from Qiagen) and aluminium oxide membranes,   diatomaceous earth particles, carboxylated or silica magnetic beads, polymers (i.e. polyethyleneimine) or specialized chromatography resins (i.e. DEAE cellulose).