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Analytical Chem JoVE (Open Access) Citable · DOI

A Simple Way to Measure Ethanol Sensitivity in Flies

DOI: 10.3791/2541-v
What you'll learn
  • ✓ Assemble a simple ethanol exposure chamber for Drosophila
  • ✓ Measure loss of righting reflex as a sedation endpoint
  • ✓ Calculate ST50 (sedation time 50%) from mobility data
  • ✓ Assess acute ethanol sensitivity and tolerance in flies
Protocol

A simple assay to measure the sedating effects of ethanol on Drosophila flies, based on the loss of righting reflex, is described.

Difficulty
beginner
Total time
~1–2 hours per experimental cohort
Model organism
Drosophila melanogaster
Biosafety
BSL-1

Steps

1
Gather materials for exposure chamber

Collect all necessary equipment and supplies including glassware, ethanol, and monitoring apparatus as listed in the materials section.

▶ 00:47
2
Construct ethanol exposure chamber

Assemble the exposure chamber apparatus following standard protocols to ensure consistent ethanol vapor saturation and fly containment.

▶ 01:40
3
Expose flies to ethanol vapor

Place flies in the assembled chamber and initiate ethanol exposure, maintaining controlled conditions throughout the exposure period.

▶ 02:38
4
Observe and record fly mobility

Monitor flies continuously and record the time at which each fly loses its righting reflex, defined as inability to right itself within a specified period.

▶ 03:57
5
Apply standardized mobility scoring rules

Use consistent criteria to determine whether a fly has lost righting reflex, ensuring reproducibility across replicates and experimenters.

▶ 05:29
6
Calculate sedation time 50 percent

Analyze righting reflex loss times to determine ST50—the time at which 50% of the fly population loses righting reflex.

▶ 06:39
7
Interpret sedation results

Present and analyze ST50 data to characterize ethanol sensitivity in the fly strain or treatment group being tested.

▶ 07:59
8
Assess tolerance development in flies

Repeat exposures and compare ST50 values across successive ethanol exposures to measure acute or rapid tolerance.

▶ 09:37
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