May 14, 2025
Preparing fly-food spoons for Drosophila embryo collection
- 1Department of Biological Sciences, Lehigh University
- Shropshire Lab
Protocol Citation: J. Dylan Shropshire 2025. Preparing fly-food spoons for Drosophila embryo collection. protocols.io https://dx.doi.org/10.17504/protocols.io.bp2l6ywervqe/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: May 13, 2025
Last Modified: May 14, 2025
Protocol Integer ID: 218148
Keywords: Drosophila, embryos, fly food, collection, eggs
Abstract
This protocol details the preparation of fly-food spoons for the collection of Drosophila embryos. These spoons are designed for placement within standard plastic Drosophila vials, primarily for the purpose of counting embryos from single-mating pairs. The method can be adapted for use with various standard fly food recipes. However, we advise against using this protocol for collecting embryos intended for downstream processing. The soft consistency of the food can make embryo removal challenging and is likely to result in significant food carryover.
Materials
Materials
- diH2O
- Cling wrap
- Conical tube, 50 mL
- Drosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104
- Droso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200
- Fly food in 500 mL or 1 L beaker
- Food coloring, blue (McCormick Culinary Blue Food Coloring)
- Inactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106
- Kimtech Kimwipe delicate task wipesKimberly-ClarkCatalog #34155
- Liquinox Biodegradable Cleaning CompoundThomas ScientificCatalog #2902N20
- Narrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL
Equipment
- Baking trays
- Ice-cream spoons (Karat U2450 2.9" PS Disposable Tasting Spoon)
- Microwave
- Syringe, 30 mL (we use glass)
Protocol materials
Kimtech Kimwipe delicate task wipesKimberly-ClarkCatalog #34155
Inactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106
Liquinox Biodegradable Cleaning CompoundThomas ScientificCatalog #2902N20
Drosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104
Narrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL
Droso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200
Narrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL
Drosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104
Droso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200
Inactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106
Kimtech Kimwipe delicate task wipesKimberly-ClarkCatalog #34155
Liquinox Biodegradable Cleaning CompoundThomas ScientificCatalog #2902N20
Safety warnings
This protocol involves the use of various chemicals and reagents that require careful handling and strict adherence to safety guidelines to ensure safe laboratory practices. Please review the Material Safety Data Sheets (MSDS) for each reagent before beginning the protocol and take appropriate precautions. All steps should be performed while wearing gloves, a lab coat, and eye protection.
Before start
- Sterilize the working surface with 10% bleach and 70% ethanol.
- Prepare fly food in a 500 mL or 1 L beaker. We use this protocol:
Protocol
CREATED BY
J. Dylan Shropshire
Prepare fly-food spoons
Prepare fly-food spoons
1h 15m
1h 15m
Align clean spoons on a large metal baking tray (as pictured, below).
10m
Using a microwave, heat a beaker of fly food until boiling.
Once it begins to boil, remove the beaker from the microwave and stir.
Repeat this process until the food is evenly heated to boiling.
Note
Keep the beaker lightly covered with cling wrap to prevent splashing.
If left unattended, the food may quickly overflow from the beaker.
10m
Add 0.1 g of Drosophila Agar, Gelidium, 100 MeshGenesee ScientificCatalog #66-104 per 100 mL of fly food.
Mix well.
2m
(Optional) Add blue food coloring until the food is the desired color (as pictured, in ).
Mix well.
Note
Food coloring is added to improve embryo visibility.
If using a darker molasses-based food, adding food coloring is not recommended.
2m
Using a 30 mL syringe, move the food from the beaker to the individual spoons.
Note
Spoons containing bubbles are usable; however, flies commonly lay their embryos within the resulting depressions. This can complicate subsequent embryo counts.
10m
Use a Kimtech Kimwipe delicate task wipesKimberly-ClarkCatalog #34155 to clean away any misplaced food before adding the spoons to Drosophila vials.
2m
Cover the tray of spoons with an upside-down baking tray.
Allow the food to solidify.
10m
While waiting for food to solidify:
Clean the beaker, syringe, and utensils.
2m
In a 50 mL conical tube, prepare a 1:1 v/v mixture of Inactive Dry Yeast, Nutritional FlakeGenesee ScientificCatalog #62-106 and diH2O.
2m
Apply a thin, even layer of yeast paste to the surface of the solidified food on each spoon using a brush. Complete coverage of the food surface is not required.
Note
Yeast is added to attract flies to the spoon and encourage egg laying.
5m
Cover the tray of spoons with an upside-down baking tray.
Allow the yeast paste to dry.
5m
Add spoons individually to Narrow Drosophila Vials, Polystyrene, Reload SystemGenesee ScientificCatalog #32-109RL and cap with Droso-Plugs, Narrow Vials, Manual InsertionGenesee ScientificCatalog #59-200 .
Note
Carefully insert each spoon into a vial with the food-bearing end positioned towards the bottom.
Exercise caution during insertion to prevent dislodging the solidified food from the spoon.
If the food slides off the spoon, consider adding more agar in .
15m
Store at Room temperature if using within 24:00:00 .
Otherwise, store at 4 °C for up to 48:00:00 .
Note
To prevent drying, avoid prolonged storage.
If stored refrigerated, allow spoons/vials to equilibrate to room temperature before introducing flies.
Clean fly-food spoons
Clean fly-food spoons
1d 8h 12m
1d 8h 12m
Loosen food from spoons by submerging them in a covered beaker filled with 1 % (v/v) Liquinox Biodegradable Cleaning CompoundThomas ScientificCatalog #2902N20 and tap water Overnight .
16h
Remove loosened food debri by thoroughly rinsing the spoons under running tap water.
10m
Dry spoons by placing them on a layer of paper towels Overnight .
16h
Store clean spoons in zip-lock bags or in covered beakers.
2m