SNAP Beta-Lactam ST Plus

Detects more beta-lactam residues including cephalexin at or below established maximum residue limits.

  • Test cold milk right from the truck, refrigerator or bulk tank
  • Robust and flexible
  • Cow, Goat, Sheep, Mare, Buffalo, Camel
  • Variety of milk types (Normal, UHT, Sterilized, reconstituted milk powder, thawed, skimmed)
  • Read results after 6–8 minutes
  • ILVO validated
  • Lowest rate of false positives

* Availability / Distribution: Worldwide

All IDEXX ST tests are submitted for ILVO validation.

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Test details

Part numbers and sizes

99-0009838 (30 tests)

Related products

Sensitivity Table


Drug European MRL FDA Tolerance SNAP Beta ST Plus Detection Level (at or below), ppb
Penicillin G (Benzylpenicillin) 4 ppb 0 ppb* 2 ppb
Ampicillin 4 ppb 10 ppb 4 ppb
Amoxicillin 4 ppb 10 ppb 2 ppb
Oxacillin 30ppb - 3 ppb
Cloxacillin 30 ppb 10ppb 3 ppb
Dicloxacillin 30 ppb - 4 ppb
Nafcillin 30 ppb - 4 ppb
Cephapirin 60 ppb 20ppb 25 ppb
Ceftiofur 100 ppb 100 ppb 9 ppb
Desfuroylceftiofur 100 ppb 100 ppb 30 ppb
Cefquinome 20ppb - 12 ppb
Cefalonium 20 ppb - 18 ppb
Cefazolin 50 ppb - 18 ppb
Cefacetrile 125 ppb - 90 ppb
Cephalexin 100 ppb - 40 ppb
Cefoperazone 50 ppb - 20 ppb
Cefuroxime - - 8 ppb

*The FDA has established a target testing level of 5 ppb for penicillin
MRL is established for cephapirin as the sum of cephapirin and desacetylcephapirin
FDA tolerance is established for ceftiofur as the marker residue, desfuroylceftiofur

Questions & Answers

About SNAP ST tests 

The SNAP Beta-Lactam ST Plus Test and the SNAPduo ST Plus Test contain a proprietary reformulated conjugate pellet that accurately and reliably detects beta-lactam and tetracycline antibiotic residues including cephalexin without heat or incubation, allowing you to test cold milk directly from the truck, refrigerator or bulk tank. The IDEXX SNAP Beta-Lactam ST Plus Test performance has been validated by an independent lab (ILVO).

To achieve optimal results close to the Maximum Residue Limits, using a heater block is not recommended. If a heater block is used by mistake, follow the prescribed protocol to retest the sample without the heater block.

It’s easy. Review the SNAP test protocol for ST tests.

SNAP ST Plus tests are completed in 6-8 minutes.

Tests that were taken out of refrigeration to be used during the day may be returned to refrigeration as long as the room temperature during the day did not exceed 30°C.

For optimal results, run the test on a flat, level surface.

Refrigerate all SNAP test materials at 2–8°C (36–46°F). Tests can be kept at 15-30°C (59-86°F) during the day of use. SNAP ST Plus tests may be stored at 15–22°C (59–72°F) for up to 30 days. Check labeling for test-specific instructions. Remove only the number of tests to be used for the day.

Yes, the test is designed for use under normal ambient conditions (15–30°C). Remove the number of devices needed for the day from refrigeration and allow them to warm to room temperature for at least 15 minutes before using.
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.

After the reagent pellet has dissolved, 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. 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.


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.