Today in the lab I was breaking up bacteria to extract a gene I inserted into them. The tubes shown in the image below contain the leftovers of some bacteria which I cultured overnight.
In addition to the normal chromosomal DNA, bacteria also contain a type of DNA called a plasmid. I have genetically engineered a plasmid so that it contains the gene sequence from a human. I then wanted to create a lot of copies of the human gene quickly, therefore, I used a method called "plasmid preparation". This is because bacteria multiply very quickly and therefore they copy their plasmids many times, producing large amounts of the human gene overnight. I then lysed the bacteria (i.e., I broke them open with chemicals) so that they released all the plasmids which I then purified and used for my subsequent experiments.