An alcohol oxidase dipstick rapidly detects methanol in the serum of mice.
BACKGROUND
Patients presenting with ingestions of methanol and ethylene glycol pose a significant challenge to emergency physicians. The decision to initiate antidotal therapy must be made quickly and is currently based on the presence of indirect signs, symptoms, and laboratory tests, because no real-time diagnostic test exists to measure these substances.


OBJECTIVE
To determine whether a commercially available ethanol-in-saliva detecting dipstick (ALCO-Screen) would be a reliable and rapid indicator of toxic alcohol presence in the serum of an animal model.


METHODS
Fifty mice randomly received intraperitoneal doses of methanol, ethylene glycol, or ethanol to induce serum concentrations of approximately 5-400 mg/dL. Thirty minutes after injection, serum was obtained. Serum was both applied to the dipstick and frozen for definitive concentration determination by gas chromatography. After 2 minutes, dipsticks were evaluated for color change by a blinded observer and photographed to be evaluated by other blinded observers at a later time.


RESULTS
All concentrations of methanol > or =5 mg/dL consistently caused a color change on the ALCO-Screen. Ethylene glycol reliably caused a color change at > or =300 mg/dL. There was significant agreement among multiple observers whether or not color change had occurred using the ALCO-Screen.


CONCLUSIONS
A commercially available dipstick that uses an alcohol oxidase colorimetric reaction reliably and rapidly detects very low serum concentrations of methanol but not ethylene glycol in this animal model. This color change is easily detected by most observers.
Department of Emergency Medicine, Brody School of Medicine, East Carolina University, Greenville, NC, USA. hackj@ecu.edu
Jason B
JB
Hack
Jacqueline
J
Early
Kori L
KL
Brewer
D000429:Alcohol Oxidoreductases / Q000032:analysis*; D000818:Animals; D003116:Color; D003124:Colorimetry; D003429:Cross Reactions; D004195:Disease Models, Animal; D000431:Ethanol / Q000032:analysis / Q000506:poisoning*; D019855:Ethylene Glycol / Q000032:analysis; D000432:Methanol / Q000097:blood*; D051379:Mice; D008810:Mice, Inbred C57BL; D019095:Point-of-Care Systems; D012463:Saliva / Q000737:chemistry*; D013997:Time Factors
D000431:Ethanol; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D019855:Ethylene Glycol; D000432:Methanol