Microbiology Methods for ERP Review 3-2020

198

Solus One Salmonella Method .— ( a ) Ensure that the heating block reaches a temperature of 85–100°C 1 and the sample is heated for 15–20 min thus ensuring the organisms are killed and the sample is safe to 2 handle. 3 ( b ) The Stop Solution contains sulfuric acid which is corrosive. Wash immediately with large 4 quantities of water if the solution comes into contact with skin or mucous membranes. 5 ( c ) For use in laboratory facilities with qualified trained personnel for the handling of potentially 6 pathogenic organisms. 7 ( d ) Training is recommended to first time users and can be provided by Solus Scientific Solutions 8 Ltd. 9 ( e ) As a guide, the following precautions should be taken as a minimum: Protective clothing 10 should be worn including safety glasses, laboratory coat and gloves where appropriate. 11 Dynex DS2 .— Improper use of the Dynex DS2 may cause personal injury or damage to the instrument. 12 For safe use, the Dynex DS2 must be operated only by qualified laboratory personnel who have been 13 appropriately trained. 14 Enrichment .— Salmonella is a Biosafety Level 2 organism. Biological samples such as enrichments have 15 the potential to transmit infectious diseases. Follow all applicable local, state/provincial, and/or national 16 regulations on disposal of biological wastes. Wear appropriate protective equipment which includes but 17 is not limited to: protective eyewear, face shield, clothing/laboratory coat, and gloves. All work should 18 be conducted in properly equipped facilities utilizing the appropriate safety equipment (e.g., physical 19 contaminant devices). Individuals should be trained in accordance with applicable regulatory and 20 company/institution requirements before working with potentially infectious materials. All enrichment 21 broths should be sterilized following any culture based confirmatory steps through heat denaturation by 22 autoclaving at 121°C for 15 min. 27 proprietary media supplement, Solus One Salmonella supplement, for the rapid and specific detection of 28 Salmonella species in select foods and environmental samples. 29 Solus One Salmonella relies on antibodies attached to the wells of microplate strips by non ‐ covalent 30 biological interactions that are highly specific to Salmonella antigens. Samples are heat treated and an 31 aliquot is added to the antibody coated wells. 32 Salmonella specific antigens present in the samples will bind immunologically to the antibody. After 33 washing to remove unbound material, an enzyme ‐ labelled antibody will bind to the captured proteins 34 and thus to the well. After a second wash step to remove any unbound enzyme ‐ antibody, the enzyme 35 substrate is added. The substrate reacts in the presence of the enzyme producing a blue color change in 36 the sample well. The substrate reaction is stopped after 30 minutes with the addition of dilute sulfuric 37 acid changing any blue color present in the wells to yellow (3). Optical densities resulting from this color 38 change are read within 10 minutes in a generic plate reader using a 450 nm filter (e.g. a microplate 39 reader or a Dynex DS2 instrument plate reader), where a result of an OD 450 < 0.200 is considered to be 40 negative for the target pathogen and OD 450 ≥ 0.200 is considered to be positive for the target pathogen. 41 23 24 25 26 A. Principle Solus One Salmonella is an antibody ‐ based high sensitivity ELISA method paired with media and our

8