Total Collaborative Study Protocol_Solus One Salmonella v1 1

with 225 ± 2.25 mL of Universal Pre‐enrichment Broth (UPB) and homogenized for 2 min by swirling. For 

NFDM, the 25 ± 2.5 g portions were enriched with 225 ± 2.25 mL of Brilliant Green Water (BGW) and 

also homogenized for 2 min by swirling. Each sampling sponge was enriched in 225 ± 2.25 mL of Lactose 

Broth, whereas each sampling swab was enriched with 90 ± 0.9 mL of Lactose Broth. The sampling 

sponges and swabs were homogenized for 2 min by hand and vortex respectively. Following 

homogenization, test portions were allowed to stand for 60 ± 5 min at room temperature (24 ± 2°C), and 

if required, the pH of all matrix enrichments was re‐adjusted to 6.8 ± 0.2 before being incubated for 22–

26 h at 35 ± 2°C. Following incubation, 0.1 ± 0.02 mL and 1.0 ± 0.10 mL of each primary enriched sample 

was transferred into 10 mL of RV Broth and 10 mL of TT Broth respectively. RV broths were incubated in 

a circulating water bath for 22–26 h at 42 ± 0.2°C. For food matrixes containing low microbial 

backgrounds (<10 4  CFU/g) such as shredded cheddar cheese and non‐fat dry milk powder, TT broths 

were incubated in a circulating water bath for 22–26 h at 35 ± 2°C. In contrast, food matrixes containing 

high microbial backgrounds (>10 4  CFU/g) such as raw salmon fillet and bagged Romaine lettuce, TT 

broths were incubated in a circulating water bath for 22–26 h at 43 ± 0.2°C. The secondary enriched 

samples were culturally confirmed as described in the reference method BAM Ch. 5, Section D through 

E.9; before final confirmation was conducted using the Bruker MALDI Biotyper biochemical identification 

method, AOAC OMA 2017.09 . 

Comparison of the candidate Solus One  Salmonella and reference methods for all matrixes indicated 

un‐inoculated test portions were all negative, high inoculation level test portions were all positive and 

fractional levels were achieved at the low inoculation level test portions using both manual and 

automated sample preparation methods where appropriate.  

As per criteria outlined in Appendix J of the Official Methods of Analysis Manual, fractional positive 

results were obtained for each matrix (3). The POD analysis between the candidate Solus One

Page 32 of 47