SNAPduo™ ST Plus Test

  • 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 minutes
  • ILVO validated
  • Lowest rate of false positives

All IDEXX ST tests are submitted for ILVO validation.

SNAPduo ST Plus Test

For information or to order:

Call IDEXX, 00800-727-43399.

Sensitivity Table
DrugEuropean MRLSNAPduo ST Plus Detection Level (at or below), ppb
Benzylpenicillin4 ppb2 ppb
Ampicillin4 ppb4 ppb
Amoxicillin4 ppb3 ppb
Oxacillin30 ppb3 ppb
Cloxacillin30 ppb4 ppb
Dicloxacillin30 ppb4 ppb
Nafcillin30 ppb3 ppb
Ceftiofur100 ppb8 ppb
Cephapirin60 ppb30 ppb
Desfuroylceftiofur100 ppb25 ppb
Cefquinome20 ppb16 ppb
Cefalonium20 ppb14 ppb
Cefazolin50 ppb20 ppb
Cefacetrile125 ppb50 ppb
Cephalexin100 ppb30 ppb
Cefoperazone50 ppb35 ppb
Cefuroxime8 ppb
Tetracycline100 ppb16 ppb
Oxytetracycline100 ppb18 ppb
Chlortetracycline100 ppb40 ppb
Doxycycline25 ppb

Questions and Answers about SNAP ST Plus tests 


Note: IDEXX SNAP ST tests are not available in the U.S. or Canada.


What is the difference between the SNAP Beta-Lactam ST Plus Test or the SNAPduo ST Plus Test and other IDEXX SNAP 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).


How long does it take to run a SNAP ST PLus test?

SNAP ST Plus tests are completed in less than 7 minutes.


What happens if I use a heater block?

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.


Can tests be returned to the refrigerator if not used that day?

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.


Must the SNAP device be on a level surface to run properly?

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


How should I store my SNAP tests?

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.


Do SNAP tests need to be brought to room temperature before testing?

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.


How important is the activation time of the SNAP test?

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.


SNAP technical tip—When to "SNAP"



Questions and Answers about Ordering and Shipping


How can I order from IDEXX?

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


How long will it take to receive my order?

Please contact your local IDEXX customer service for any order.


What if I need to change or cancel an order or have other questions?

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.