How to make a LilBubome – Step 1: Extract DNA

You might have already seen it in the video or in our last lab note: We recently received a blood sample from LilBUB. The blood was taken from her during her routine medical check-up with her vet, Dr. Woodruff.

And now that the sample has arrived in our lab, we can start the actual work! For this, what we need to do first, is to extract the DNA from the blood sample. Might sounds sophisticated, but actually: not at all!!!!

DNA extraction is composed by 2 main steps:

1. Cell lysis: Our DNA is contained deep inside the cell, in a structure called the nucleus. Therefore we first need to break open the cell. For this we use detergents,the stuff that’s contained in washing up liquid. Just think about washing the dishes: when you use detergent it not only removes dirt, but also the grease (fat) from them, right? Well, cellular membranes are composed mainly of fat molecules. When detergent is added, their structure gets destabilized and DNA is released.

Cell lysis of BUB’s blood. Like every good detergent, it foams up when you shake it.

2. DNA precipitation: After breaking open the cell, you get something like a DNA-soup, where the DNA is dissolved in the liquid. To work with it, we need to actually extract it. We do this by adding salt and highly concentrated alcohol to our liquid. This will make the DNA highly insoluble, causing it to appear as white floating strings that we can collect and use for our future experiments.

As you can see the three main ingredients to extract DNA are detergent, salt and alcohol. So you actually can extract your own DNA at home!!!!! Check this:

However, for the extraction of LilBUB´s DNA, we use highly pure reagents and a more exhaustive protocol, since we want to get the cleanest possible DNA for sequencing.

There it is – the tube with BUB’s extracted DNA.

– Dario