I am using the PureLink Microbiome DNA Purification Kit (Cat. No. A29790). When should I remove the swab?
The swab should be removed after incubation, prior to bead beating.
Does the elution buffer in the PureLink Microbiome DNA Purification Kit (Cat. No. A29790) contain EDTA?
Yes, the elution buffer in the PureLink Microbiome DNA Purification Kit contains EDTA. An alternative that does not contain EDTA is Tris Buffer (10 mM Tris-HCl, pH 8.0-9.0). Eluting in water is possible, but the low pH of water could lead to reduced stability and less accurate OD readings.
When using the PureLink Microbiome DNA Purification Kit with soil samples, I am getting less than 400 µL supernatant after lysis. Can you provide me with any suggestions?
For some samples, including soil and stool samples, it can be difficult to withdraw 400 µL supernatant while avoiding debris. If less than 250 µL of supernatant is transferred, add S1-Lysis buffer to bring the volume to 400 µL, before adding S3-Cleanup Buffer.
I am getting low yield using PureLink Microbiome DNA Purification Kit. How can I improve the yield?
Low yield could be caused by inefficient lysis and/or low levels of DNA in the sample. Please try heating samples at 95 degrees C for 5-10 minutes instead of 65 degrees C for 10 minutes after adding S2-Lysis Enhancer. Bead beat for a longer time or at a higher power setting. You can also try to perform the experiment with more starting material, but do not exceed what we specify in the protocol. However for some challenging samples, too much starting material can also result in low yield. In this case, please try less starting material and/or increase the volume of S1-Lysis Buffer.
There are inhibitors in the isolated DNA from environmental samples using PureLink Microbiome DNA Purification Kit. Is there a way to rescue it and obtain good PCR results?
There are several options to rescue your DNA obtain good PCR results including diluting your DNA sample, using specific enzymes, and/or using an additive. The methods are described below:
- Dilute your DNA sample 10-100 times prior to PCR which will dilute out the contaminants while the PCR signal in many cases will remain strong.
- Use tough enzymes that were specifically designed and optimized to be effective in harsh environments, and work in the presence of high levels of inhibitors, for instance, TaqPath qPCR Master Mix, CG Reagent.
- Use a BSA additive for the PCR reaction. In most cases, if used at appropriate concentration, BSA can rescue your sample.
You can also try repeating the purification with less starting material or increased volume of S1-Lysis buffer. Additionally, after the addition of the S3- Cleanup buffer, you can try incubating the sample for 10 minutes on ice before centrifugation.