Magic...

. . . not really, but that's what DNA extraction seemed to me before learning the science behind it. In fact, it's quite simple! The process varies from kit to kit and lab to lab, but over all follows the same major steps. The DNA I am trying to extract came from all the mouths and cloaca of the frogs that were swabbed in the field. I want to get this DNA to come off the cotton swab and sit suspended in a solution which I will be able to pipette into the PCR machine (we'll talk about the PCR later).

My lab station set up with samples ready to go!

Maintaining constant pH throughout the process is very important -- this can be done with the aid of a buffer, such as phosphate buffered saline, added to the vial containing the swab before starting the extraction process. Next, a detergent and lysis agent are added to the sample. The detergent (not to be confused with laundry soap . . . although somewhat similar) breaks apart the cell membrane and nuclear envelope. This is important because it exposes the DNA which is wound around a protein called a histone. The lysis agent, usually a proteinase K, cleaves the histone releasing the DNA into the solution. Adding alcohol to the sample causes the DNA pieces to come out of the solution and clump together. And finally, filtering out the ethanol and adding a final buffer to the sample ensures that DNA is evenly distributed within the liquid in the vial and ready to be tested or frozen for later use. Tada! DNA has been successfully extracted from a cotton-tipped swab!

Pipetting... measuring is done in MICROliters... tiny amounts!

Samples floating in a warm water bath to speed up the detergent and lysis solution processes

Samples ready to be spun in the centrifuge