Histamine Enzyme Strip
Principle
When total amine screen is positive, use a commercial histamine-specific enzyme strip for confirmation and quantification.
These strips use histamine dehydrogenase enzyme to catalyze oxidation of histamine specifically. The resulting electron mediator reduces a formazan (MTT) dye — color intensity is directly proportional to histamine concentration. Highly specific — the enzyme only acts on histamine, not other biogenic amines.
Product
BioAssay Systems QuantiQuik Histamine Quick Test Strips
- Catalog: QQHIST10
- ~$8/test (pack of 10)
- Detection range: 0-200ppm (undiluted)
- Sample types validated: fish, red wine, white wine, milk
- Response time: <15 minutes
- Requires pipette for dilution steps
Available at: bioassaysys.com
Procedure
Follow manufacturer instructions exactly. General workflow:
- Prepare sample extract per strip instructions (may differ slightly from unified prep — verify)
- Apply to strip
- Read color against included chart at specified time
- Use dilution factor to back-calculate original concentration
When to Run
Only after positive total amine screen. See Total Amine Screen triage table.
High-risk food categories worth confirmatory testing:
- Cured/fermented meats (salami, jerky, prosciutto)
- Aged cheese
- Fermented vegetables (sauerkraut, kimchi)
- Canned fish
- Leftovers (histamine builds during refrigeration)
- Overripe produce
Cost Management
At ~$8/strip, be selective. The AuNP triage screen should filter most samples. Budget ~1-2 strips per high-risk food category when first characterizing a new food source.
Notes
- Histamine adsorbs to glass — use plastic tubes throughout
- Fresh meat baseline: ~1-2 mg/kg histamine (physiological muscle level)
- Concern threshold: 35ppm (FDA fish action level); 50ppm (EU/Codex)
- MCAS-sensitive individuals may react at much lower levels — the strip gives a number, individual threshold varies
References
- BioAssay Systems product page
- Comparison study: MaxSignal enzymatic vs Veratox ELISA vs Reveal LFIC (ScienceDirect 2011)
- Histamine Testing Methods