Association for Biology Laboratory Education

Quick DNA Isolation from P. fluorescens
 



Tested Studies in Laboratory Teaching, 2010, Volume 31

Samuelsen, A.

Abstract

A number of procedures have been developed for DNA isolation from a variety of sources. The procedure presented here is an extension of a KOH lysis protocol used to differentiate Gram-negative from Gram-positive bacteria. Gram-negative bacteria will lyse in 3% KOH, whereas Gram-positive will not (Schumann & Jasalavich, 2001). Pseudomonas fluorescens was chosen for student work because it is a harmless soil bacterium, unlike its pathogenic cousin Pseudomonas aeruginosa. However, this procedure will likely work for several different Gram-negative bacteria. Since DNA is negatively charged and glass rods carry a net positive charge, a glass rod was used to spool the thread-like DNA out of solution. The isolated DNA was then re-hydrated and subjected to DNA- specific enzymes, the effects of which were visualized using DNA gel electrophoresis.

Keywords:  isolation, Pseudomonas fluorescens

University of Delaware (2009)