Dealing with humic and fulvic acids sprayed on cannabis plants—especially when testing for pathogens like HLVd—can be tricky because these substances can inhibit PCR reactions by binding to nucleic acids or interfering with enzymes used in the assay.
Sample Preparation & Processing
- Thorough Rinsing of Samples: If foliar applications of humic or fulvic acids are used, rinsing the plant material with sterile water before testing can help remove surface residues.
- Use of RNA Extraction Kits with Inhibitor Removal: Opt for kits that include steps specifically designed to remove inhibitors. We recommend using PurePrep Plant Lysis.
- Dilution of Extracts: Diluting your RNA extract (e.g., 1:10 or 1:20) before testing can help reduce inhibitor effects without significantly compromising sensitivity.
Validation & Testing
- Use of Internal Controls: Including an internal amplification control in your qPCR reaction can help detect inhibition if it occurs.