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Biofilms are composed of bacteria irreversibly attached to a substrate by extracellular polymeric substances or EPS. Within this EPS matrix, a number of compounds can be found including humic substances, metals, salts, and pesticides. As a result, microbes within a biofilm are difficult to lyse and the nucleic acids, once purified, may still contain inhibitory substances. The PowerBiofilm™ DNA Isolation Kit and PowerBiofilm™ RNA Isolation Kit from MO BIO Laboratories combine biofilm pretreatment and improved cell lysis with patented inhibitor Removal Technology® to yield consistent, high-quality, inhibitor-free DNA and RNA.
EPS removal and lysis optimizationOne of the most difficult aspects of nucleic acid isolation and purification from biofilms is ensuring complete lysis of the microbial community in the presence of EPS. EPS degradation can be achieved a number of ways using chemical, mechanical, or enzymatic means. The PowerBiofilm™ kits use a combination of several methods to dissolve the EPS, which in turn fully exposes the microbes to the lysis buffers (Figure 1, A and B).
Inhibitor removal
Even with efficient lysis, degraded EPS and other organic/inorganic compounds can carry over through purification and inhibit downstream applications of nucleic acids. To prevent this, both the PowerBiofilm™ DNA and PowerBiofilm™ RNA Isolation Kits contain patented Inhibitor Removal Technology® (IRT), which has been shown to remove humic substances, polysaccharides, and polyphenolics from nucleic acid preps (www.mobio.com/references).
Sample validationBiofilms occur virtually everywhere and are as diverse as the microbes that create them. Therefore, a wide range of biofilm types have been evaluated both at MO BIO and by outside collaborators (Table 1, A and B). High DNA and RNA yielding biofilms were tested as well as low yielding microbial mats.
