SNAP Gentamicin Test

Detects gentamicin residues at or below the U.S. FDA-established action level.

  • Ensures that residues from this common mastitis antibiotic are within regulatory limits.
  • An essential tool in your milk quality-assurance program.

* Availability / Distribution: Worldwide

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Test details

Part numbers and sizes

99-0009840 (30 tests)

Related products


Sensitivity Table


Drug FDA Safe Level European MRL/th> 90/95 Detection Level
Gentamicin 30 ppb 100 ppb At or below 30 ppb

Questions & Answers

About SNAP tests 

Note: The following questions do not apply to SNAP ST tests.

SNAP tests take less than 10 minutes to run.

Please refer to your package insert for test-specific storage requirements. Refrigerate SNAP NBL Tests at 0–7°C (32–45°F). Refrigerate all other non-ST tests at 2–8°C (36–46°F).  Tests can be kept at room temperature, 18–29°C (64–84°F), during the day of use. Remove only the number of tests to be used for the day.

No, you do not need to warm the tests prior to use; you can run the SNAP tests directly out of the refrigerator. Do not open the foil pouch until you're ready to run the test.

Before you test:

  1. Verify that the SNAP device has colored spots in the results window and activation circle.
  2. Make sure the pellet is moving freely in the bottom of the sample tube.
  3. Be sure your heater block has been preheated to a temperature within the 45°C ±5°C range.

SNAP tests must be run at 45°C ±5°C (104–122°F). The SNAP portable heater blocks have internal thermostats optimized within the range of 40–50°C. Allow 10–15 minutes for the portable heater to reach operating temperature. If you do not see any color in the block’s temperature strip, do not attempt to run the test. Contact IDEXX Technical Services if you have any questions about heater performance. Call 1-800-321-0207 or 1-207-556-4496, Monday–Friday, 8:00 a.m. to 5:00 p.m. ET; fax 1-207-556-4630; or contact us.

Yes, the SNAP test must remain on the heater block at 45°C ±5°C for the duration of the test—during the incubation time, the activation time and the color-development time.

Activation time is critical. After the initial incubation, pour the entire contents of the sample tube into the sample well of the SNAP device. Remain with the device and watch the sample flow across the results window toward the blue activation circle. When the blue activation circle begins to disappear, press the activator firmly until the device "snaps" and the activator is flush with the body of the SNAP device. Always activate (snap) the device when the edge of the circle nearest the sample begins to turn from dark blue to white. Do not let the circle completely disappear.


The number of SNAP tests you can run at one time depends on the type of heater block you have. With the preset portable models that IDEXX offers, you can accommodate two SNAP devices at one time.

If you're running multiple samples, set up all samples and SNAP devices on the heater, then set a timer for the incubation period. After incubation, individually pour the samples onto the sample well of each device. Watch the devices carefully as each sample may flow at a different rate. Activate each device as the individual activation circles begin to disappear. Snap the devices completely, and set a timer for the appropriate color-development time (it varies by test) after the last device has been activated. When the time period is complete, you can read the results.

We have answered the most frequently asked questions here to help you get started. When you receive your order, you will also receive detailed printed instructions that fully outline how to use your SNAP heater block and your SNAP tests. Anytime you have questions, you can call IDEXX Technical Services, 1-800-321-0207 or 1-207-556-4496, Monday–Friday, 8:00 a.m. to 5:00 p.m. ET; fax 1-207-556-4630; or contact us.

Ordering and shipping

You can place your order with our Customer Service department by calling 1-800-321-0207 or 1-207-556-4496 or 00800-727-43399 (Monday through Friday, 8:00 a.m. to 6:00 p.m. ET). Orders can also be faxed to 207-556-4630, or sent via email to

Please contact your local IDEXX customer service for any order.

In most cases, we process orders the same day we receive them. To ensure we receive any changes as soon as possible, please call one of our customer service representatives at 1-800-321-0207 or 1-207-556-4496 or 00800-727-43399(Monday through Friday, 8:00 a.m. to 6:00 p.m. ET). You can also send a fax to IDEXX at 1-207-556-4630.

Still have questions?
IDEXX backs all tests with a dedicated team of professionals available to answer your product, regulatory and dairy-industry questions. Call IDEXX Technical Services at 1-800-321-0207 or 1-207-556-4496 or 00800-727-43399, Monday through Friday, 8:00 a.m. to 5:00p.m. ET; or complete the contact form.