MO BIO recently launched a method for the isolation of DNA and RNA from a very difficult sample type called biofilm. In a previous article, we explained some of the difficulties associated with working with biofilm and biomats. These sample types are not like any other environmental sample and require specialized chemistry to break through the EPS and liberate cells for lysis. 

During the ISME 13 conference in Seattle, WA, last week, the most common question we received from the scientists visiting our booth was: What is the difference between PowerSoil and the new PowerBiofilm DNA Kit?

Today I will explain in greater detail for our readers how these two innovative and specialized methods differ and how they are the same.

1.The Bead Tube

The PowerBiofilm kit has a new bead tube that contains a mixture of glass and ceramic beads. The mixture of beads allows for success in lysis of both biofilm and biomat samples which can vary in their consistency, moisture, and content.

The PowerSoil Kit and the PowerLyzer PowerSoil Kit have bead tubes containing one bead type. The original PowerSoil DNA Isolation Kit has the garnet bead tube that comes pre-filled with homogenization buffer. The sharp garnet rocks are irregularly shaped and break down soil and fecal matrices very effectively with minimal shearing to DNA. The garnet bead is not as hard as glass so will be effective using the vortex for homogenization. For lysis using high powered bead beaters, the 0.1 mm glass bead tube in the PowerLyzer PowerSoil Kit is the perfect choice. Some soils, such as clay and sediment, will extract more efficiently using these fine glass beads. In our studies using multiple soil types, a mixture of glass beads did not result in higher yields than the 0.1 mm glass alone.  For this reason, we are using a single bead type.

2. Chemistry

The PowerBiofilm kit has a unique chemistry for melting polysaccharides and breaking down EPS. It is a combination of solutions that when mixed become activated and will dissolve the sticky substances making bead beating more effective. Over-beating EPS will result in loss of DNA or RNA. By melting it prior to bead beating, higher yields are obtained using less harsh homogenization conditions.

The PowerSoil Kit does not use this novel EPS dissolving chemistry. The IRT system in PowerSoil is sufficient to remove polysaccharides that may be present from residual plant debris in the soil

3. IRT

Inhibitor Removal Technology (IRT) is used in both the PowerBiofilm and PowerSoil Kits. Humic acids are also abundant in biofilm and biomats and so removal is necessary for most samples. The PowerSoil kit has always contained this patented chemistry for achieving high purity DNA from soil.

4. Purification with Silica Technology

Both the PowerBiofilm and PowerSoil kits use silica spin filter purification technology for the isolation of nucleic acids after extraction and removal of humic acids. DNA is eluted in tris buffer and ready to use for your next step.

5. PowerBiofilm RNA Kit

We only have an RNA method for the PowerBiofilm Kit in a small scale miniprep. The RNA kit differs from the DNA kit by the solution used for binding nucleic acids to the silica column. We bind RNA to the silica membrane using different salt concentrations and solutions. We also included the on-column DNase system for removal of genomic DNA from the membrane before elution of RNA. This saves times having to perform post-extraction processing at the end.

For RNA from soil, we have the RNA PowerSoil Kit which starts with much more sample (2 grams) and has a robust lysis using phenol. The final purification uses anion-exchange resin technology to result in very high purity RNA and the option of DNA elution in a separate tube. Because the RNA content of soil is so low, starting with more soil is generally preferred. An article with tips and tricks for this kit is on our blog.

We also previously wrote up some tips and tricks for the PowerBiofilm Kit. Take a look at these if you are using this kit. And as always, please feel free to contact us anytime at technical@mobio.com.  Advice comes straight from R&D scientists who developed or use these kits all the time and know how to troubleshoot any problem.

These are the basic differences between these kits. Some people told us they used the PowerSoil Kit for their biofilms now.  The PowerSoil may work for some types of samples where the EPS may be low or where the biomass is high. For the most consistent yields and purity from biofilm and biomat, try the PowerBiofilm Kit chemistry. Request a sample of the PowerBiofilm Kit from our website today.