Simple Homemade Tools to Handle Fruit Flies—Drosophila melanogaster

Summary

Described here is the use of several homemade tools to transfer, chill, and kill adult Drosophila, as well as to clean glass culture vials and collect eggs. These tools are easy to make and are rather efficient in handling Drosophila.

Abstract

The fruit fly, Drosophila melanogaster, is widely used both in biological research and biology education. Handling adult flies is common but difficult in practice, as adult flies fly. Demonstrated here is how to make some simple and cost-effective tools to address difficult issues in the handling of Drosophila. Holes in foam stoppers are made and pipette tips or funnels are inserted into the holes. Flies then move only in one direction into the pipette tip/funnel assemblage, allowing efficient control of the transfer of adult Drosophila into or out of a vial. Existing protocols have been modified for cool-anesthetizing flies by chilling in crushed ice and transferring them onto a cold, hard icepack surface. The icepack is covered with a piece of medical gauze that keeps immobilized flies from the condensed water when examined under a stereomicroscope. The flies are finally euthanized for counting and sorting or discarded by microwaving. A bottle-shaped cage has also been developed for collecting eggs, as well as a labor-saving device and accompanying protocol for cleaning glass culture vials.

Introduction

The fruit fly, Drosophila melanogaster, is a model organism widely used in biological research and biology education to study a wide range of topics^1,2. The basic problems of handling Drosophila are the transfer of adults from vial to vial and immobilization of the flies so they are easier to handle, as all adults (except for some mutants^3,4) can fly.

Conventionally, a researcher transfers flies from one vial to another by holding two vials mouth-to-mouth, tapping the flies down or allowing flies to fly up ....

Protocol

1. Preparing Tools and Accessories

1. Tip/funnel stoppers
   1. Obtain two sponge plugs (the diameter of the plugs must be slightly larger than the internal diameter of the vials used to transfer flies). Make a hole in the centers of the sponge plugs with a heated electric soldering iron.
   2. Obtain two 1 mL pipette tips, cut one in half transversely with a sharp knife, and discard the pointed end. Then, cut 1.5 cm of the pointed end off the second pipette tip. Glue the remains of the two pipette tips together with an all-purpose adhesive to make an elongated pipette tip (Figure 1A).
   3. Inser....

Results

The T- and F-stoppers were developed as a set of simple tools that can be adapted and used in any fly transferring activities. Transferring flies from an old culture into several fresh cultures involves removing the plugs of the fresh vials, replacing them with F-stoppers, then tapping down the flies in the old vial, quickly removing its plug, and replacing it with a T-stopper. If the old food is compact, then it is important to flip the old vial and insert the tip of T-stopper into the o.......

Discussion

Some homemade tools for handling basic activities involved in Drosophila rearing and experimentation are described in this paper. These tools are simple but rather effective. Virtually, any lab can make these tools with ease, and a research or a teaching laboratory does not need to find a ready-made alternative that is perhaps not available locally.

Fly transferring is the most common practice and a difficult task in Drosophila experiments. Unfortunately, until now, there hav.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
A pair of pliers
Cordless drill driver			max speed: 500 rpm
Electric soldering iron
File
Funnel			diameter of disk<60mm
Ice box
Insect pins
Infrared thermometer			HCIYET HT-830
Long cuff rubber gloves
Mechanical pencils
Medical gauze
Microcentrifuge tube			100 ul
Microwave oven
Parafilm
Peri dish			internal diameter 60 mm
Pipette tips			1 ml
Plastic film
Plastic Peri dish			Φ36 mm used to cover the empty vial
Point tweezers
Protective work gloves
Re-freezable hard icepacks			26.5×14.5×2.5 cm or larger
Rubber air blower
Snap cutter
Soft drink bottle			500 ml, internal diameter c.a. 65 mm
Sponge stopper
Stainless steel sponges
Tube brush
Vial			Φ34 mm × 90 mm