I am working on high altitudes medicinal plants, my work is based on DNA isolation and my samples are preserved in 70% ethanol from last 6 months. We can use CTAB method for DNA isolation?????
" Modification of a CTAB DNA extraction protocol for plants containing high polysaccharide and polyphenol components" Please check the this publication
Dear all, during my trial of DNA isolation from preserved leaves in ethanol by CTAB method, we have these kind of bands. Please send me your valuable suggestions.
You should be able to isolate genomic DNA (gDNA) from those plant tissues preserved in 70% ethanol. However, you should be aware that the quality of the gDNA you isolated may change. There are some reports claiming that 'degradation' of gDNA or lost of DNA from materials preserved in ethanol occurred (see below). If this happens, your experiments (ex. genotyping with markers) might show a minor difference in the banding profiles between DNA from fresh tissue and DNA from ethanol-stored.
For examples:
1. In the paper ("Extraction of high-quality DNA from ethanol-preserved tropical plant tissues") mentioned by Salamma Sugali above, the spinach gDNA degraded when Spanish was stored in ethanol even with a short time (reference #16).
2. Another paper showed that DNA was lost from specimens after prolong storage in ethanol (see attachment #1). Although those specimens have been stored in ethanol for a much longer time (260 years) than your materials (6 months). In the paper, the authors discussed the possible reasons for DNA lost during ethanol storage (see yellow highlights).
3. Since your samples are stored in 70% ethanol, not 95% or higher, there are some concerns of that as stated in this attached paper (see attachment, yellow highlights):
"70% ethanol is often used instead of 96% because it is cheaper and keeps specimens somewhat flexible, allowing for later morphological study. 70% ethanol however also means that there is 30% of other things in this liquid (mostly water), and this causes degradation of DNA. "