Using 3D-printed equipment to standardise experiments

Sometimes you just have to improvise in the lab. Here is a timelapse of me designing and 3D printing something for standardising an assay for my experiments.

Timelapse: The process of designing and making 3D-printed lab equipment.

I have to perform a migration assay after inhibiting a protein of some immortalised cells. To do that I have to track the position of individual cells over time, to see if they have migrated from one place of the dish to another.

But the dish has a 100 mm diameter and each cell is about 4 μm in diameter so how can I know that every time I place the dish under the microscope I am looking at the exact same group of cells? (There are over 20 million cells in the dish!).

Well, I solved this problem by printing a simple piece of plastic of specific dimensions that I can put underneath the dish. The plastic covers the entire bottom of the dish, apart from five locations where there are holes. The holes have the diameter of the field of view when looking down the microscope. I can look through these holes every time I have to check the cells, to ensure I am looking at the exact same spot repeatedly over time.

A simple solution! All you need to know is some geometry formulae and basic programming. What are your thoughts? Do you have any suggestions of how this could be improved?

I made the code for this 3D print available on my GitHub page here.