Ideally, sampling equipment should be ordered sterile and be individually wrapped and single-use to minimise the risk of introducing contaminant DNA from sampling equipment to environmental samples. Sampling kits purchased from NatureMetrics only contain sterile, single-use components. We are continually striving to reduce plastics in our kits and actively promote recycling. If any equipment must be decontaminated and reused (note that no equipment for GCN eDNA survey should be reused between sites apart from surveyor PPE), then bleach sterilisation is the accepted method.
Bleach must be purchased at a stock concentration of 3-6% sodium hypochlorite (higher is better) from a supermarket, cleaning service or laboratory supplier. The stock bleach should be diluted 1:10 with purified or deionised water (e.g. 1 L of stock bleach to 9 L of purified water). Where purified water is unavailable, mineral water purchased from a supermarket should be used. This dilution creates a 10% bleach solution. You should submerge non-metal and non-electrical equipment in the 10% bleach solution for at least 10 minutes but ideally 3 hours or overnight. After this time, remove equipment from bleach and thoroughly rinse (at least 3 times) with purified or deionised water. After rinsing, place equipment on fresh paper towel and leave to dry overnight. Metal equipment should be submerged for 5 minutes before rinsing and drying overnight. Surfaces of electrical equipment should only be wiped with 10% bleach, followed by 70% ethanol.