Report 6 - Unknown #4 - Name: Yesenia Tolentino & Jessica...

A . We were given the unknown organism # 4 and we put them into two categories A and B . In order to prepare for our template DNA , we added 100μl of distilled water into the two 1.5 ml microfuge tubes . Then , with a sterile inoculating loop , we pick up a small loopful of each unknown and dispensed it into its assigned microfuge tube , and used the vortex to break any clumps . Afterwards , we lysed the cells for 10 minutes by placing the microfuge tubes on a hotplate , and after we placed it in the centrifugation for 10 minutes at maximum speed . After centrifuging , there should be a clear supernatant which is a clear fluid above the settlement at the bottom of the tube . Finally , after all the steps have been completed we have the template DNA for both of our unknowns A and B. B. The name of the target DNA used for the identification is the 16S Ribosomal DNA ( 1540 bp ) . C. This region of identification was used because of the other unusable ribosomal DNA ’s . The 23S rDNA is too big for sequencing and the 5S r DNA is too small for sequencing . The 16S rDNA is just the right size for sequencing . Another reason we choose this region was because it has regions that are highly conserved in all prokaryotes and regions that are variable across species . D. The size of the target DNA in E. coli is 779 bp .