Foreign Perspectives

The morning went in preparing our samples for the PCR machine. Lots of pipetting samples in minuscule amounts, ice buckets and taking a of care to make sure our own DNA didn’t contaminate the samples. Quite a busy morning which finished with us assembling the gel for our agarose gel electrophoresis in the afternoon as it takes quite a while to set. Actually, the one consistent theme for this week seems to be that business of waiting around for something to set or be mixed and the like.

What the PCR setup sequence does is to slice out the bit of DNA that we were interested in ie CCR5-delta-32. That’s an interesting sequence as people that don’t have it are essentially immune to HIV, hence the focus on it through this summer school. Anyway, the PCR takes that bit out and produces millions of copies of it, increasing the concentration of the gene segment enough that it can be detected by the gel we used in the afternoon.

The gel process separates out the various proteins in the post-PCR mixes depending on the size of the fragments (their original shape doesn’t matter as the PCR process chops up the DNA or rather amplifies just the fragments that you want to look at). After half an hour or so it’s finished but you can’t see anything until the gel is placed under UV illumination as the dye used is UV sensitive which is a shame as you can’t see the proteins moving along the gel.

The various gaps in the day were filled in by the theory behind it all though, mainly, running behind the practical bits.

We’d our first SXR376-exclusive lecture this evening on genetic variation (the one last night on transposons was shared with SXR375) followed by the optional one on giving a research presentation.