AlPlanta 1 article published in JoVE Biology Homemade Site Directed Mutagenesis of Whole Plasmids Mark Laible1, Kajohn Boonrod2 1Department of Biology, Johannes Gutenberg-University Mainz, Germany, 2Proteomics division, AlPlanta, Neustadt an der Weinstrasse, Germany Site directed mutagenesis of whole plasmids is a simple way to create slightly different variations of an original plasmid. Here we demonstrate an easy and cost effective way to introduce base substitutions into a plasmid using standard reagents.