NanoDrop Pioneers! (Legionella pneumophila Blog Week 4)

Last Friday Josh showed our group (Daisy, Zaira and me) how to use the new NanoDrop machine! It was awesome to be the first ones to learn how to use it and actually get to run our samples through it.  Daisy even taught Bethany how to run her samples in the NanoDrop. 
     The NanoDrop measures the concentration of DNA in the any given sample.  It also has the ability to determine the purity of DNA in a tested sample by measuring the ratio of absorbance measured at wavelengths of 260nm and 280nm.  DNA tends to absorb at a wavelength of 260nm while protein, phenol and other contaminants absorb at a wavelength of 280nm (NanoDrop, 2007).  By comparing the two measurements, the NanoDrop is able to determine purity of DNA.  A ratio measurement for reasonably pure DNA would be around 1.8.  As you will see in the attached image, our samples do not display this type of purity.  The lowered purity is expected because our samples, as of now, do not contain purely DNA. The samples have other contaminants that affect this reading.  Daisy and Zaira have cut DNA samples out of agarose gels after PCR in the past and their results actually were aligned with what would be expected for pure DNA.  So we will get there soon!

NanoDrop, http://www.bio.davidson.edu/gcat/protocols/NanoDrop_tip.pdf