Now that you have your purified plasmid, you will need to get an idea of its quality. Transfection efficiency is highly influenced by the quality of the plasmid, so it’s important to get a full picture. There are a few factors to plasmid quality, and you will want to look at all of them to make sure your samples will be successful in your downstream processing. Here, I will explain how to measure the absorbance ratios of your sample, successfully read an agarose gel, and the importance of low endotoxin values.