Medichem’s disinfectant, Trigene, can be a valuable resource in veterinary, medical, and molecular labs as it is manufactured in accordance with ISO 9000:2000 accreditation standards and is very inexpensive when compared to similar products on the market. I first used Trigene after seeking alternatives to the use of sodium hypochlorite on benches, plastic products and floors, as well as, the use of UV lamps to degrade DNA contaminants. Initial applications that I found for Trigene were primarily non-laboratory based such as cleaning reptile cages, batteries, pet bedding, SCUBA diving regulators and a disinfectant for body piercing. At the time, the information available regarding Trigene was limited and only available on the internet. My interest was peaked when I found that Trigene is composed of a safe combination of chemicals (non-toxic, non-corrosive, non-irritant, and non-hazardous and does not contain phenols, chlorines or aldehydes) with potential drying of the skin as the only potential side effect. The usual laboratory precautions should be in effect when using this product and any other product.
The formulation of Trigene is virucidal, bactericidal, fungicidal, sporicidal, tuberculocidal and bio-degradable and it may be used on virtually any surface. Although pathogens may develop resistance to many treatments, even in a three-pronged disinfectant approach (such as in the case of treating serious human diseases), Trigene actually has a four-pronged approach, thus reducing resistance acquisition. The inclusion of alkyl dimethyl benzyl ammonium chloride within the solution acts as a long chain quaternary ammonium compound (QAC), long known to be an effective disinfectant. The ingredient dodecylamine sulphamate contracts the cell wall and then completely strips it with a second proposed action of cell death via inactivation of energy producing enzymes.
I’ve tested the Trigene reagent at our working dilution of 1:50 and compared that with 5% sodium hypochlorite on intact cells and on purified DNA in a mock contamination scenario using nuclease-free water as a control. Intact mammalian cells from a culture were put on a bench-top with several replicates and allowed to dry. Some were then cleaned with Trigene, others were wiped down with sodium hypochlorite and the control was wiped with water. All were given a second wipe with water as this is the recommended method for Trigene. An uncleaned area was used as a reference. These areas were then swabbed and DNA was extracted by the Chelex DNA extraction method, quantities measured by a real-time PCR method with a built in inhibitor control. This experiment was replicated using purified genomic DNA. Results showed no significant inhibition of PCR showing that wiping down the area with water after Trigene or sodium hypochlorite cleaning does not leave PCR inhibitors. In comparison to the reference areas the DNA quantification showed that Trigene was most effective in removing all of the DNA and cellular material. Sodium hypochlorite cleaning came in second with minor cellular and DNA contamination remaining and the water last of all. Cleaning with water showed a level of decontamination suggesting that the mechanical action of cleaning assists in removal of contaminants.
Trigene is used in our laboratory at a dilution of 1:50 to clean pipette barrels, benches, centrifuges, safety cabinets, tube racks etc. Essentially it is used to clean almost anything that can be contaminated in the daily running of a biological laboratory.
When dealing with contaminated areas, such as safety cabinets, pipettes or benches, a dilution of 1:50 or 1:100 seems fine for most pathogens, however, 1:50 is the recommended dilution. Depending on the pathogen, you may want to use different dilution ratios. Molecular biology laboratories in particular can benefit from Trigene, as it can be used in both post-PCR and fluorescence (I have tested it with FAM, JOE, NED, ROX and LIZ and it did not show any fluorescence). The other Trigene benefits are not just from its disinfectant action, but also based on its ability to alter the secondary structures of DNA/RNA down to their base level, thus eliminating the risk of associated contamination. In addition, it will reduce any open primers, templates, extracts or PCR products to unusable material. For this reason, Trigene should not be sprayed ubiquitously in a molecular lab as critical samples can potentially be damaged. Also related to the previous point is the importance of wiping down instruments used with molecular samples with water prior to using them for experimental applications. MediChem has a wide range of goods to use so use your common sense when using Trigene. Trust me it works very well as long as it is used properly.
David Fegredo
Medical Scientist
PathWest
Australia