Having heard of how beneficial the in2scienceUK scheme was for students such as myself, applying for a STEM degree at university, my expectations were set high for the 2 week research placement – confirmed to be held at Bath University. It’s safe to say that I was not disappointed and that the experience I gained during my time in the labs has given me a truly valuable insight into research not only at a university level but as a remarkable career option too.

Though my group were fortunate enough to have the opportunity to carry out a multitude of experiments whilst at the university, our predominant investigation focused on mimicking the drug screening process by testing the effect of three different drugs (5-fluorouracil, camptothecin and hydrogen peroxide) on the viability of HeLa cancer cells.

We began by preparing the HeLa cells on which we would later test each drug and this involved growing the single strain provided on three separate agar plates – each containing Nematode growth medium. All petri dishes were incubated overnight at optimal growth conditions (38 degrees and 5% CO2) to ensure the rapid proliferation of the cells. We then proceeded to make up the required concentrations of each drug by calculating the correct ratio of stock (initial concentration of drug) and medium. A 96 well plate was used with 6 replicates for each concentration of each drug (3 per drug) and included a positive control (bleach to ensure induced cell death) as well as negative controls (no HeLa cells and no drug).

Laura H fig 1

After leaving the cell/drug mixture overnight, an MTT assay (a colorimetric assay used to assess cell metabolic viability) was carried out the following day. The principle of this technique is based on the fact that the mitochondria in viable cells contain functional enzymes that are capable of reducing the dye into insoluble purple crystals. Thus, the viability of cells is reflected in the richness of the purple colour produced which is assessed using a colorimeter.

Our results reflected findings from previous research as 5-fluorouracil was most effective at its highest concentration as this is a drug commonly used in chemotherapy. It works by acting as an analogue of uracil with a fluorine atom replacing the hydrogen attached to C5 thus preventing the biosynthesis of pyrimidines and has an inhibitory effect on DNA replication thus cancer cells cease to replicate. Camptothecin is a more experimental drug however it shows promise for future clinical use as demonstrated within our results.

Laura H fig 2


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