AOAC ERP MICRO AUGUST 2018

Table 998.09B. Statistical analyses of results for 3M TECRA assay with selective enrichment in Rappaport-Vassiliadis (R10) broth only compared to BAM, 7th Ed.

Incidence of false negatives among total positive suspensions, % d VIA Culture

Incidence of false positives among total negative suspensions, % f VIA Culture

Sensitivity rate, % e

Specificity rate, % g

MPN a (CFU/g)

Method agreement, % b

c 2 c — h

Food (No. labs)

VIA Culture

VIA Culture 100 91 98 98 100 98 99 100 100 100 100 100 100 100 100 100 100 96 100 99 100 99 100 100 100 100

Milk chocolate (14) <0.003

100 100 100

— — — — 0

8.6

0.009 0.093

— 0.0

0.0 0.0

100 100 100 100

1.72 2.3

0.0 0.0

0.0

0.0

2.1 0.0

Dried whole egg (13) <0.003 98.5

— — — — 1.5

0.0 0.0 (2.8r) i

0.009 98.5

2.8 100 (97r) 97 1.1 (0.0r)

0.0 99 (100r) 100

0.430

100 100

— 0.0

0.0

100 100

0.0

0.0 0.0 0.0 0.0 4.0 0.9 1.3 0.0 0.0

Nonfat dry milk (18) <0.003

— — — — — 0.0

0.24

98.8

0.0 0.0

1.3 0.0

0.0 0.0

99 100 100 100

0.0 0.0

2.4

100 100

Black pepper (15) <0.003

— — — — — 0.0

0.014 97.3

0.5

5.4

0.0

95 100

0.0

0.088 <0.003

100 100 100 100 100 85 90

— 0.0

0.0 100 (95r) 100 0.0 (1.2r)

1.2 100 (99r) 99

Soy flour (15)

— — — — — 0.0

0.24

— 0.0 — 0.0

0.0 0.0

0.0 0.0 0.0 0.0

0.0 0.0

2.4

— — — — — 5.0 (6.6v) i 55

Raw turkey (12) (BAM, 7th Ed.)

<0.003 0.043

95 (93.3v) 45

0.4 10.5 0.16 6.9

5.3 3.4

89.4 94.7 93.1 96.5

1.6 0.0

7.9 4.8

98.4 92.1 100 95.2

0.46

a–i See Table 998.09D for footnotes.

Dextran D9260 produced by Leuconostoc mesenteroides strain B-512, 0.06 g hydrolyzed gelatin, 0.0024 g CaCl 2 × 2H 2 O, and 120 ng thimerosal. Reconstituted conjugate is stable for 2 months when stored at 2 ° –8 ° C. ( f ) Conjugate diluent .—Two vials (13.5 mL/vial). Contains 0.42 g Na 2 B 4 O 7 × 10H 2 O, 0.193 g CaCl 2 × 2H 2 O, 0.22 g hydrolyzed gelatin, and 0.0022 g thimerosal in H 2 O. ( g ) Substrate .—One vial (lyophilized). Contains 0.011 g 2,2 ¢ -azino-di(3-ethylbenzthiazoline sulfonate) and 0.123 g NaH 2 PO 4 × 2H 2 O. Reconstituted substrate is stable 2 months when stored at 2 ° –8 ° C. ( h ) Substrate diluent .—One vial (22 mL/vial). Contains 0.116 g citric acid, 0.0011 g H 2 O 2 , and 0.0185 g NaOH in H 2 O. ( i ) Stop solution .—One vial (6 mL/vial). Contains 0.15 g NaF in H 2 O. ( Caution : Do not pipet by mouth; avoid contact with skin. In the event of a spill, sweep or pipet contents into beaker and dilute with H 2 O. Dilute remainder of spilled stop solution with H 2 O.) ( j ) Wash solution concentrate .—One vial (25 mL/vial). Contains 1.45 g tris, 7.03 g NaCl, 1.0 g Tween, and 0.0025 g thimerosal in H 2 O. ( k ) Color comparator card .—For visual interpretation of positive and negative tests. ( l ) ULTIMA additive .—Additive solution for RV[R10] broth prior to heat-killing step. Contains hydroxymethyl aminoethane and polyoxyethylenesorbitan monolaurate in water. ( m ) M broth .—Not required for ULTIMA Immunoassay. 5.0 g yeast extract, 12.5 g tryptone, 2.0 g mannose, 5.0 g anhydrous

sodium citrate, 5.0 g NaCl, 5.0 g anhydrous K 2

HPO 4

, 0.14 g

anhydrous MnCl 2

, 0.8 g anhydrous MgSO 4

, 0.04 g anhydrous

FeSO 4 , and 0.75 g Tween 80 (available from BD Biosciences). O and heat to boiling 1 ! 2 min. Dispense 10 mL portions into 16 × 125 mm screw-cap test tubes. Cap tubes loosely and autoclave 15 min at 121 ° C. Tighten caps securely for storage. Final pH should be 7.0 ± 0.2. ( n ) Diagnostic reagents .—Necessary for culture confirmation of presumptive positive EIA tests; see 967.25 B ( see 17.9.01). C. Apparatus ( a ) Incubators .—36 ° ± 1°C and 42 ° ± 1°C. ( b ) Multipipets .—Delivering 20 and 200 m L for immunoassay and 1 and 0.1 mL for enrichment. ( c ) Water bath .—Maintaining 100 ° C. Autoclave set at 100 ° C is acceptable alternative, as are generators of flowing steam. ( d ) Plastic squeeze bottle .—500 mL, for dispensing wash solution. Automatic washer may be used. ( e ) Plastic film wrap .—To cover wells during incubation. ( f ) Enzyme immunoassay reader or dual wavelength reader .—Optional. Photometer with 414 ± 10 nm screening filter, or dual wavelength reader with filters at 414 ± 10 nm and 490 ± 10 nm, which will read through microtiter plates. D. General Instructions Components of kit must be refrigerated when not in use. Kit is intended for one-time use only; do not reuse wells containing food, reagents, or wash solution. Suspend ingredients in 1 L H 2

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