Alkali Denaturation Test (APT and Downey)
Test Code
Clinical Significance
Alkali Denaturation Test (APT and Downey) - The Alkali Denaturation Test (APT) is useful in distinguishing between newborn swallowing mother's blood and fetal gastrointestinal bleeding (Melena neonatorum).
The APT test is used to determine whether blood in the diaper, vomitus, or feces of a neonate contains predominantly the baby's or the mother's blood. It is a crude, qualitative method based on resistance of hemoglobin F to alkali denaturation.
Test Resources
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Test Details
Methodology
Reference Range(s)
Alternative Name(s)
Preferred Specimen(s)
2 mL of a random, bloody stool submitted in a plastic leak-proof container
Alternative Specimen(s)
2 mL bloody vomitus or bloody mucus, submitted in a plastic leak-proof container or bloody diaper submitted in a plastic leak-proof container
Minimum Volume
1 mL
Collection Instructions
Note: The specimen requirement for this test is a grossly bloody (red) non-tarry stool (or bloody vomitus, bloody mucus or blood-stained diaper from newborn within 1 day of birth). If the specimen submitted was not bloody and we were unable to elute any red color from it, the test cannot be performed and will be cancelled
Transport Container
Plastic leak-proof container
Transport Temperature
Room temperature
Specimen Stability
- Room temperature: 7 days
- Refrigerated: 7 days
- Frozen: Unacceptable
Reject Criteria
Received frozen
Setup Schedule
Refrigerated: 7 days
Frozen: Unacceptable