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Figure 8. Stability
mericon
E. coli STEC O-type assay
There was no decrease (right shift)observed between the time points t=0 @ 4
+ 1
o
C, t=4 months @ 4 + 1
o
C. Storing the prime-probe lots had, therefore, no
deleterious effect on the performance of the assay in the first 4 months of
storage. Stability studies are ongoing. Dilution series 10,000 copies/µl to 10
copies/µl
Discussion
The
mericon
E. coliO157 Screen Plus and
mericon
E. coliSTEC O-TypePathogen Detection
Assays, using both the manual and automated DNA extraction procedures, successfully
recovered
E. coli
non-O157:H7 STEC’s and
E. coli
O157:H7fromfresh spinach, raw ground
beef (70% lean), and raw beef trim. Using POD analysis, no statistically significant
differences were seen between the number of positive samples detected by the candidate
methods and the reference methods for all three matrixes tested.
The results of the inclusivity and exclusivity study demonstrated 100% agreement with
expected results for the test panel.
The robustness study demonstrated that the
mericon
E. coliO157Screen Plus and
mericon
E. coliSTECO-Type Pathogen Detection Assays were sensitive to changes after 8 and
9 (
E. coli
STEC O-Type only) but not 10 hours of incubation.
The
mericon
E. coliO157Screen Plus and the
mericon
E. coliSTEC O-Type Pathogen
Detection Assaysare quick and easy to perform, providing results within 15hoursfor 30
sample replicates for both the manual and the QIAsymphony (automated) preparation
methods, including the pre-enrichment time. The QIAsymphony adds the benefit of
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00
0 months
4 months
Ct
Storage, months
mericon E. coli O-type assay: O157:H7
stability
10000 1000 100 25 10
OMAMAN-36 E/ AOAC PTM Report
ERP Use Only
January 2017
AOAC Research Institute
Exp rt Review Panel Use Only