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Appendix III. Instructions for Sample Randomization and Blind Coding
AOAC International Collaborative Study
ANSR
Salmonella
Confirmation Test
Instructions for Sample Randomization and Blind Coding
Following are instructions for randomization and blind-coding of the collaborative study test samples. A
randomization scheme is provided below. To maintain the integrity of the blind-coding, it is important
that only Operator 1 at each collaborative site have access to or knowledge of the randomization/coding
scheme. Operator 2 will perform the ANSR testing with the randomized and coded samples provided by
Operator 1.
After cultures are streaked and incubated, write the coded numbers on the plates exactly as shown in
the table below. Use these same coded numbers on the tubes containing the PBS colony resuspensions.
Culture
Agar Medium
Coded Number (Example)
AA
HE
8
AA
XLD
69
AA
BS
61
AA
XLT4
67
AA
BGS
71
AA
DMLIA
11
AA
TSA
54
BB
HE
6
BB
XLD
83
BB
BS
39
BB
XLT4
82
BB
BGS
15
BB
DMLIA
28
BB
TSA
42
CC
HE
1
CC
XLD
80
CC
BS
25
CC
XLT4
33
CC
BGS
38
CC
DMLIA
68
CC
TSA
36
DD
HE
7
DD
XLD
34
DD
BS
26
DD
XLT4
23
DD
BGS
46
DD
DMLIA
43
DD
TSA
74
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