L1-The Assay

overview – assay –  neuro & ageing – definitions – neuro & flies – statistics

Key objectives and learning outcomes:

The climbing assay is a simple and cheap, yet powerful experiment used in contemporary fly research on ageing and neurodegeneration (see here). The climbing assay is a didactically valuable school experiment that teaches curriculum-relevant laboratory skills through using real model organisms and reflecting state-of-the-art research in modern science laboratories. This experiment has therefore purpose and relevance, ideal to excite, inspire and engage students. If you would like to do this experiment in your school, a fully worked-out lesson can be downloaded here. The experiment includes the following GCSE and A level aims:

• Organise data into tables and graphs.
• Interpret and describe trends in data.
• Understand sample size.
• Understand experimental design and how aspects of the method relate to reliability, reproducibility and precision.
• Calculate the mean and identify outliers.

It also introduces to a number of biology concepts:

• Understand ageing as a biological phenomenon.
• Understand the principal idea of neurodegenerative diseases and their causes.
• Understand basic principles of nervous system function.
• Understand how Drosophila can contribute to the investigation of ageing and neurodegenerative diseases.

What equipment is needed?

Time your fly collection so that you have young wild-type Drosophila flies (eclosed only days before starting the experiment; equivalent to teenagers) and aged flies (5-6 weeks old; equivalent to grandparents). Per group you will need:

• Two pairs of empty fly tubes/vials taped together. One pair of tubes contains 10 young flies, the other contains 10 old flies.
• A cardboard panel with scaled horizontal lines placed upright behind the flies.
• A stopwatch to time the measured climbing period.
• A camera or phone to take photos of the vials in front of the cardboard scale after 15 seconds, thus documenting how far the flies have climbed up during that period.
• Optional: A printer, so that the photos can be more easily analysed, or if phones are not used to document and view data.

How is it done?

• Before you start, formulate a (null) hypothesis:
  • Is there a difference between old and young flies?
  • Which group of flies do you predict to climb the tube faster?
  • Why do you think this?
• Tap the tubes 1-3 times on the table, just hard enough that all the flies fall to the bottom

• Immediately start the stopwatch.
• After 15 seconds, take a picture of the flies in front of the cardboard scale using your phone or a camera.
• Print the picture or view it on the phone to count how many flies are in each section of the scale.
• Plot your data on graph paper.
• Perform statistical analysis of your data and the data across the class to test your hypothesis (see the available spreadsheet below).
• Explain applications of this experiment in current research on ageing and neurodegeneration (see the available documents below).

 Support documents

• A KS3 school lesson as Powerpoint, accompanied by support materials (lesson plan and background information, instructions for setting up the experiment, how to obtain flies and fly food, a film of the experiment, an Excel spread sheet to perform statistical analysis of the obtained data, a risk assessment) can be downloaded here (scroll to top of page for respective zip file).
• For further help and advice contact the Manchester Fly Facility.

overview – assay – neuro & ageing – definitions – neuro & flies – statistics

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