This image has been inverted to the negative, after digital photography of the gel while exposed with uv radiation on a gel box.  The DNA has been interchelated with ethidium bromide that was present in the gel at the time of electrophoresis.  DNA migrated through this 0.8% agarose gel for 5 minutes at 100 Volts, so that we could roughly tell how much DNA was present in each student-prepared sample.  The image on the top indicates the sample #; these sample #'s are those listed in the environmental sample library except for samples e2, g1 and F (these are other unknown phages we are currently studying).  Students prepared DNA using the phage DNA preparation protocol.  DNA was not found in samples 19, 26 and 9 (perhaps we made a mistake with these samples during the DNA isolation procedure).  The DNA ladder allows for determination of DNA molecular weight, providing the different band sizes that comprise the ladder can be resolved (this gel has not run long enough for that).  A low concentration of DNA was found in sample 36, look close.  This experiment allows us to determine how much DNA we will digest tomorrow, when we compare the restriction digestion patterns that these different phage genomes have.  7 uL of each phage DNA prep was loaded onto the gel, with 2 uL of loading dye added to the DNA. 

As Chiara said, "Wow, nobody has ever studied these DNA before...we are the first to ever see them."