Question

Question 12 1 pts You are given a tube containing a mixture of two unknown organisms. In correct order, what do you think would make sense to do as the first three steps/tests (steps that have to be carried out in performing individual tests don't count, so don't detallthese) that you would go through in trying to Isolate and identify the two organisms? O do gram staining prepare slants, do quadrant streaking O do gram staining do quadrant streaking, run blochemical tests O grow on slants, do quadrant streaking run blooctrical tests write down unknown tube, do quadrant streaking do gram staining O grow on slants, do gram staining, run blochelcal tests O run blochelcal tests (sim or pr-lactose), do pram staining grow on slants Question 13 1 pts In a Virus Plaque Assay (see course lab manual) what is diluted before adding it to soft agar and what else is added to the soft agar before pouring it

Answer 1

1) The tube having two unknown bacteria first has to be labeled. After labelling the tube, quadrant streaking is done on an luria broth agar plate, so as to isolate the colonies. Form the plate take colonies to perform Gram staining wherein bacteria is distinguished on the basis of their cell wall content. Gram positive bacteria retains the stain and thus are violet in color whereas gram negative bacteria do not retain the stain, thus are red in color.

Thus the correct answer is-

D- write down unknown tube #, do quadrant streaking, do gram staining.