A-1 Low concentration of cells or virus in the starting sample —Enrich the concentration of cells or viruses.
A-2 Insufficient lysis of the samples —The samples has not been mixed thoroughly with the lysis buffer. It is suggested to thoroughly mix by pulse-vortexing for 1-2 times. —Insufficient cell lysis caused by the activity decrease of proteinase K. —Insufficient cell lysis or protein degradation due to insufficient warm bath time. It is suggested to cut the tissue into small pieces and extend the bath time to remove all the residue in the lysate.
A-3 Insufficient DNA adsorption. —No ethanol or low-percentage instead of 100% ethanol was added before the lysate was transfer to the spin column.
A-4 The pH value of elution buffer is too low. —Adjust the pH to between 8.0-8.3.
Residual ethanol in the eluent.
—There is residual washing buffer PW in the eluent. The ethanol can be removed by centrifuging the spin column for 3-5 min, and then placing at room temperature or 50℃ incubator for 1-2 min.
A-1 The sample is not fresh. —Extract a positive sample DNA as control to determine whether the DNA in the sample has degraded.
A-2 Improper pre-treatment. —Caused by excessive liquid nitrogen grinding, moisture regaining, or too large amount of the sample.
The pretreatments should vary for different samples. For plant samples, make sure to thoroughly grind in liquid nitrogen. For animal samples, homogenate or thoroughly grind in liquid nitrogen. For samples with cell walls that are hard to break, such as G+ bacteria and yeast, it is suggested to use lysozyme, lyticase or mechanical methods to break the cell walls.
4992201/4992202 Plant Genomic DNA Kit adopts a column-based method that requires chloroform for the extraction. It is especially suitable for various plant samples, as well as plant dry powder. Hi-DNAsecure Plant Kit is also column-based, but with no need of phenol/chloroform extraction, making it safe and non-toxic. It is suitable for plants with high polysaccharides and polyphenol content. 4992709/4992710 DNAquick Plant System adopts a liquid-based method. Phenol/chloroform extraction is not needed as well. The purification procedure is simple and fast with no limit for the sample start amounts, so users can adjust the amount flexibly according to the experimental requirements. Large size of gDNA fragments can be obtained with high yield.
The blood clot DNA extraction can be performed using the reagents provided in these two kits by simply changing the protocol to the specific instruction for the blood clot DNA extraction. The soft copy of the blood clot DNA extraction protocol can be issued upon requesting.
Suspend the fresh sample with 1 ml PBS, normal saline or TE buffer. Completely homogenize the sample by a homogenizer and collect the precipitate to the bottom of a tube by centrifuging. Dispose the supernatant, and resuspend the precipitate with 200 μl buffer GA. The following DNA purification can be performed according to the instruction.
For the purification of gDNA in plasma, serum and body fluid samples, TIANamp Micro DNA Kit is recommended. For the purification of virus gDNA from serum/plasma samples, TIANamp Virus DNA/RNA Kit is recommended. For the purification of bacterial gDNA from serum and plasma samples, TIANamp Bacteria DNA Kit is recommended (lysozyme should be included for positive bacterial). For saliva samples, Hi-Swab DNA Kit and TIANamp Bacteria DNA Kit are recommended.
DNAsecure Plant Kit or DNAquick Plant System are recommended for fungal genome extraction. For yeast genome extraction, TIANamp Yeast DNA Kit is recommended (lyticase should be self-prepared).