A Day in the Lab: Extracting Plasmid DNA from Bacterial Cultures

🕒 Approximate reading time: 3 minutes

Today in the lab, I was deeply engrossed in a miniprep experiment, an intriguing process that facilitates the purification of plasmid DNA from bacterial cultures. The previous day, I meticulously prepared overnight cultures of bacteria which I had previously transformed using a vector plasmid. This plasmid incorporates a specific human gene which is fundamental to my upcoming experiments. As a result of their overnight growth, the bacteria multiplied profusely, consequently producing an abundance of gene copies. Today, my primary objective was to extract the plasmid DNA housing the gene from these bacterial cultures.

Timelapse: Diving into the preparation of bacterial samples for the extraction of plasmid DNA.

A Deep Dive into Today's Experimental Methodology

The day kicked off with bacterial lysis under alkaline conditions, leading to the denaturation of chromosomal DNA and proteins. However, the plasmid DNA, with the human gene embedded in it, remained stable throughout. This method is fondly referred to as a 'miniprep' owing to its quick and small-scale nature in isolating plasmid DNA. The yield from each bacterial culture typically ranges between 50-100 μg of plasmid DNA. An absolute wonder of modern molecular biology.