Milk Safety References
National Conference on Interstate Milk Shipments (NCIMS)

APPENDIX N BULK MILK TANKER SCREENING TEST FORM
IDEXX - New SNAP® BETA LACTAM
For Raw Bovine Milk
GENERAL REQUIREMENTS

1. __________ See Appendix N General Requirements form items 1-8 & 15

   SAMPLES

2. __________ See Appendix N General Requirements (GR) form item 9

   APPARATUS & REAGENTS

3. __________ Equipment
   1. __________ Heater block with SNAP inset thermostatically controlled at 45±5C
      1. __________ Temperature checked by placing standardized thermometer in tube containing liquid (bulb submersed) in heating unit, records maintained
      2. __________ Or, use 6 inch partial immersion thermometer placed directly into small thermometer well in middle of heating unit, records maintained
   2. __________ Single use 450 µL pipet with indicator line to measure amount of sample, supplied by manufacturer (screening only)
   3. __________ Fixed volume pipettor to dispense 450 µL (see App. N GR item 7)
   4. __________ SNAP Kit

      __________ Lot #  _____  Exp Date   _____ 

   5. __________ Sample tubes containing reagent pellet
   6. __________ Kits received refrigerated
   7. __________ Store kits at 0-7C
   8. __________ Timer
   9. __________ IDEXX Reader for SNAP devices, with printer or data download capability
4. __________ Controls [FROZEN STANDARDS NOT ALLOWED]
   1. __________ Non frozen positive control only, 5.0 ppb Penicillin G
   2. __________ Store according to label instructions

      __________ Mfg. _____ Lot #  _____  Exp. Date  _____

   3. __________ Re-hydrate as per manufacturer's instructions
   4. __________ Test for suitability each time prepared, must produce appropriate reaction, records maintained
   5. __________ Store control at 0 - 4.4C for no more than 2 days. Do not freeze
5. __________ Inhibitor Free Raw Milk (Negative Control)
   1. __________ Test for suitability each time prepared, must produce appropriate reaction, records maintained

      TECHNIQUE

6. __________ Daily Performance and Operation Check (see App. N GR item 10)
   1. __________ Read positive and negative check set devices. Both devices must read within the limits on the check set devices

      __________ Positive Range __________  Negative Range __________

      __________ If check sets fail, call IDEXX before proceeding

7. __________ Test Procedure
   1. __________ Set out required number of SNAP™ devices, sample tubes and pipets for the samples to be tested. Discard unused, un-refrigerated devices at the end of the day
   2. __________ Pre-warm heater block(s) to 45±5C, hold at 45C for at least 5 minutes
      1. __________ Check initial pre-heating with a reference thermometer, records maintained
      2. __________ Continuous use block heaters, check temperature daily with reference thermometer, records maintained
   3. __________ Label each device and each sample tube
   4. __________ Place devices on incubator block(s)
   5. __________ Mix samples/controls by shaking 25 times in 7 sec through 1 ft arc, use within 3 minutes
   6. __________ Look for blue reagent pellet in bottom of tube, if not there tap to bring pellet down
   7. __________ Remove and discard sample tube caps
   8. __________ With pipets provided, draw up controls or samples
   9. __________ (Draw up, avoiding foam and bubbles, expel and draw up again) to the indicator lines and carefully add all of the control or sample milk to the appropriately labeled tubes. (Screening only)
   10. __________ Or, using fixed volume pipettor (item 3c), draw up 450 µL of controls and samples (draw up, avoiding foam and bubbles, expel and draw up again) and carefully add to the appropriately labeled tubes
   11. __________ Use clean pipet (or tip) for each control and sample
   12. __________ Agitate sample tube to dissolve reagent pellet
   13. __________ Incubate tube(s) in heater block next to device with the corresponding ID
   14. __________ Incubate tubes for 5 minutes (use timer) at 45±5C
   15. __________ After incubation, pour contents of tubes into sample well of device
   16. __________ Watch blue activation circle, as it begins to become white push the Activator firmly until it "snaps" flush with the body of the SNAP™ device (device remains on heater block)
   17. __________ Incubate device for 4 minutes (use timer) at 45±5C
   18. __________ Read IMMEDIATELY with IDEXX Reader for SNAP devices
8. __________ Interpretation
   1. __________ The control spot is on the top and the test spot on the bottom of the Results Window (Correct orientation is with activator button to right and sample well to left)
   2. __________ Negative result:
      1. __________ If test spot is darker than or equal to the control spot, sample is Negative (NF)
   3. __________ Positive result:
      1. __________ If test spot is lighter than control spot, sample is Initial Positive
   4. __________ IDEXX Reader for SNAP devices automatically prints results as Positive (initial) or Negative (NF)
9. __________ Verification of Initial Positive Samples (see App. N GR item 11); Confirmation of Presumptive Positive Samples (see App. N GR item 12); and Producer Trace-Back (see App. N GR item 13)
10. __________ Reporting (see App. N GR item 14)