No Color or Poor Color Development - Test may not have been prespotted
- Pellet in tube may have been stuck at top and discarded inadvertently
- Heater may not have been up to temperature, 45°C ±5°C
- Sample may not have been incubated for the full 5-minute incubation time
- SNAP® device may not have remained on heater for the 4-minute color development time
- SNAP device may have been presnapped or not completely snapped
- Rerun test
High Background - Heater temperature may have been above 50°C
- Sample may have been spilled onto results window when pouring it into sample well
- SNAP device may have been activated (snapped) late
- SNAP device may not have been fully activated (snapped)
- Rerun test
Poor Spot Quality or Streaking - Abnormal-looking milk may have been used, sample may be too thick to flow
- SNAP device may have been activated too early or too late
- Air temperature may be too hot or too cold, air temperature should be 65°–85°F
- Heater temperature may have been outside of range, 45°C ±5°C
- Pellet in sample tube may have been hydrated, often caused by taking test device out of foil prior to running
- SNAP device may not have been activated (snapped) completely
- Test device may have been removed from heater block prior to the full 4-minute color development time
- Rerun test
Discrepant Results—Visual vs. SNAPshot® Reader - May be spot quality issues on device (see above)
- Background may not be clear, known as "high background" or "high blue" (see above)
- Test device may have been removed from heater block prior to the full 4-minute color development time
- Rerun test
False-Positives - Heater temperature may have been above 50°C
- Sample may have been over-incubated, correct incubation is 5 minutes
- SNAP device may have been activated (snapped) too late
- SNAP device may have been read before the full 4-minute color development time
- Poor sample integrity, sample must be well-agitated
- Rerun test
False-Negatives - Heater temperature may have been below 40°C
- Sample may have been under-incubated or incubation step skipped completely
- Poor sample integrity, sample must be well-agitated
- Rerun test
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