by Hafiza Irshad
The two weeks I spent in lab were the highlight of my summer. The equipment surpassed anything we had in school labs. No squeezy pipettes, no ball pipettes – which never seem to work and amazingly, I didn’t have to wear goggles (I was safe without them).
Aside from all the luxuries I experienced from being in a legitimate laboratory, the learning experience was incredibly satisfying. Doing my EPQ project on cancer, I thought I had a fairly sound knowledge on the development of cancer, however within the first hour of my placement Dr Laura Yates had proved me very wrong indeed.
One of the first signposts of cancer is that the adhesion between cells is lost. This enables cells to migrate to other parts of the body and possibly form tumours. The work I did with Dr Laura included staining slices of lung tissue to identify the strength of the proteins that are responsible for cell adhesion.
The first protein I stained for was E-cadherin. The protocol was fairly simple but each step was very crucial to be able to get a good stain. For example, one needs to incubate the tissue in a ‘block’ to prevent non-specific binding to any other proteins. PBS (a water based salt solution used as a buffer) washes are done after each block followed by incubation to get rid of any background staining that may prohibit the visibility of the protein stain. I repeated the process on different samples of proteins – Vangl2 and MMP12. The protocols were almost identical for all but had slight differences. For example, Vangl2 required a stronger, additional block and the secondary solution used differed too.
To get lungs thin enough to stain and observe they must be sliced. This sounds perfectly simple but it was something that definitely required a lot of experience, a gel is used to stick the sample to a block of wax, then cooling the gel until it’s hard using an ultra-cold covering. Next you place this section of lung into the slicing machine and with each slice made, you retrieve from the media (liquid containing nutrients for the cells) placed in a small tub underneath. You then place these super small slices into wells filled with fresh media.
This is what one of the slides I stained looked like under the microscope:
This branch of science is called “immunohistochemistry” and is all related to the detection of proteins within samples. Staining is an important technique used in research as it helps you prove (or possibly disprove) your theories and allows you to share your work to other scientists. I enjoyed staining because there are many techniques involved, teaching me lots in a short amount of time.