1. 1-2 Test The most widely used single unit test for Salmonella
AOAC Official Method (989.13)

2. 1-2 Test ® For Salmonella Immunodiffusion
(Antibody-based detection method)
Requires movement of salmonella specific antibodies and target antigen through semi-solid gel medium
Antibody movement - diffusion
Target antigen movement – motility of live Salmonella cells
The 1-2 Test is the most widely used test for Salmonella screening in the world. This patented single-use unit is completeyl self-contained. The 1-2 test uses a unique combination of a built-in selective enrichment, immunodiffusion and a proprietary selective preparation if antibodies for salmonella. This unique combination makes it one of the most sensitive and specific tests for salmonella.

3. 1-2 Test ® For Salmonella Single test format – 1 test per device
2 Enrichment protocols
Low microbial / Processed foods
Aerobic plate count <10,000 CFU/g
Product exposed to a processing step that reduces and controls bioburden (drying, freezing, cooking, etc…)
High microbial / Raw foods
Aerobic plate count >10,000 CFU/g
Products possess inherent antimicrobial or bacteriostatic properties (spices)
The 1-2 Test is the most widely used test for Salmonella screening in the world. This patented single-use unit is completeyl self-contained. The 1-2 test uses a unique combination of a built-in selective enrichment, immunodiffusion and a proprietary selective preparation if antibodies for salmonella. This unique combination makes it one of the most sensitive and specific tests for salmonella.

4. Enrichment Protocols 1-2 Test
Processed / Low Microbial Foods
PRE-ENRICHMENT
Time to results:
36 – 54 hours
BPW or Lactose broth @ 35 oC 24 ± 2h
Transfer to 1-2 Test
@ 35°C 14 – 30 hours
Raw / High Microbial Foods
SELECTIVE ENRICHMENT
Time to results:
44 – 62 hours
PRE-ENRICHMENT
Iodine activated TBG
@ 42 o C 6-8 h
BPW or Lactose broth @ 35 oC 24 ± 2h
Transfer to 1-2 Test
@ 35°C 14 – 30 hours

5. 1-2 Test - Procedure Position 1-2 Test unit with black cap up.
Remove cap.
Add 1 drop of Reagent #1 (Iodine-Iodide Solution) to TT Broth.
Replace cap and gently shake unit to mix.

6. 1-2 Test - Procedure Reposition 1-2 Test unit with black cap up.
Remove plug with sterile forceps and discard it.
This will allow communication
between the two chambers.

7. 1-2 Test - Procedure Transfer 0.1 mL sample into inoculation chamber
For raw foods, transfer 1.5 mL of sample/TT mixture to empty inoculation chamber (side-port)

8. 1-2 Test - Procedure
Position 1-2 Test unit with white cap up and remove cap.
Snip off tip of gel void former with shears and discard tip.

9. 1-2 Test - Procedure Add 1 drop of Reagent #2 (Antibody preparation).
Replace white cap.
Incubate.

10. 1-2 Test - Incubation 1-2 Test should be incubated with white cap up.
Use the adequate incubation temperature: 35 °C
Duration: hours
Could be incubated individually or while held in incubation tray

11. 1-2 Test ® Advanced Science. Simple to Use.
Motility Chamber
Inoculation Chamber
Diffusion of 1-2 Test antibody
Antibody well
Immunoband
Movement of Salmonella
As the Salmonella encounters the diffusing antibodies they are immobilized.
A characteristic three-dimensional Immunoband will be formed if the test is positive. Results are read visually.
Inoculation Chamber: enriched sample for analysis
Motility Chamber: semi solid Agar based motility medium
Antibody well: Salmonella specific antibodies
Salmonella, if present, moves through the selective medium into the motility chamber.
Antibody diffuses into the motility chamber in a radial pattern.

12. 1-2 Test - Reading Results
A positive test is indicated by the presence of a white band that is U-shaped or meniscus-shaped
Immunoband is 3-dimensional and is seen in all planes while rotating 1-2 Test unit.
The shape of the immunoband may vary from strain to strain. Refer to directions for use for other examples.

13. 1-2 Test – Performance Statistics
AOAC® Official Method of Analysis
Sensitivity: 98.2%
Specificity: 98.8%
False Negative Rate: 1.8%
False Positive Rate: 1.2%

14. 1-2 Test Objection Only detects motile Salmonella
Motility is a key criteria used to define the genus Salmonella (Edward’s and Ewing’s Identification of Enterobacteriaceae, 4th ed. 1986)
There are only 2 non-motile species of Salmonella, host adapted to poultry with very low virulence to humans (S. pullorum and S. gallinarum)
9 studies of the presence and distribution of Salmonella in food, feed, and dairy products – 183 species isolated with only 1 non-motile (S. pullorum from poultry facility environmental samples)

15. 1-2 Test - Benefits Labor Savings Minimal hands-on time
Processed foods- Lactose enrichment & transfer to 1-2 test
Raw foods – Single selective enrichment (TT)
Reduced media preparation
Speed
Raw – 44 hours (2 days) Processed – 36 hours (next day)
Ease of use
Least complicated Salmonella test on the market
Easy to interpret