Day 6. February 5, 2019.
Today I performed a “test assay” to practice setting up an assay in preparation for one that would actually be used for research in the lab. As a reminder, the lab studies mating behaviors of fruit flies in comparison to the genotype the flies posses. Here are the steps I followed to set up the test assay:
▶︎ Prior to today, I collected male flies of the desired genotype. Only males of the desired genotype are needed because the lab is only concerned with the male flies for primary findings. For this test assay, I used CS flies that weren't needed in the lab.
▶︎ Today, I prepared two mating chambers, which are pictured above. Each mating chamber contains 36 cells which are separated into two sections by a removable, clear plastic strip (not pictured). Each chamber has a damp paper towel to better allow the flies to cling to a surface for mating.
▶︎ I placed a virgin female fly into each cell of the two chambers, then placed the clear plastic strip over the top to create a divider in each cell.
▶︎ Normally each assay will have a control group. Because my assay was just a test, I didn’t include a control group. I just wanted to practice performing an assay. Without a control group, I just placed a normal male CS fly into each cell of the two chambers.
▶︎ I placed the two chambers in the 25℃ incubator for 15 minutes (normally, this would be done for 1.5 hours or longer) to help the effects of the CO₂ wear off. The effects of the CO₂ could affect data from the assay.
▶︎ I began the assay. The flies are monitored for an hour. I started my timer immediately after I removed the plastic strip separating the male and female flies.
▶︎ Using the table pictured above, I record the time when each fly pair starts mating. I included a labeled picture (picture 2) above to show what flies look like when they mate. It’s exactly as you’d imagine it (lol).
▶︎ When the flies stop mating, I recorded the time on the table in a square under the square of the start time. In picture 1, I labeled two squares with “start” and “end” in blue ink to help visualize this.
▶︎ At the end of the hour of monitoring the flies, I compiled the data on an excel spreadsheet to analyze the data.
I’ll be able to post the results of an actual assay when I perform it, complete with a control and experimental group!
