Lazlo's Outcome

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Petri dishes containing M. smegmatis bacteria are shown below.  The spots are where phage have destroyed (lysed) bacteria.  We also have electron-micrographs (pictures at 50,000 magnification) and DNA analysis of these phage.  We would have posted these online, but we have found out that the scientific publication copyright on certain scientific journals (PDF file, search for the word "web" within) restricts us from this.

BF-03-16 B F2                              BF-03-16 A F2 10-4

   

BF-03-16 B F2  10-4                     CP1-03-42 B F2 10-4 

    

 

The BF-03-16 A F2 plate dilution is 10-4, a similar number of phage as the -4 BF-03-16 B F2 dilution received.  To understand how many phage we are discussing, see phage dilution plating.  Notice that as the phage is diluted, the phage plaque size increases to become visible.  Smaller plaques can be seen in the -2 and -3 plates and more rarely on the -1.  The A and B phages are picked from separate plaques that were originally believed to be different species.  The plaques enlarge after exended growth; note that it also appears that the phage is temperate because of the lysogenic and lytic rings after BF-03-16 F2 (it is the same plate as the above) has been grown for an additional 24 hours.  It takes 3 days to see these plaques after top-agar plating

Note that BF-03-16 A F2, comparing to BF-03-16 B F2, has a different plaque morphology.  A and B are actually the same phage, just different plaques.  The difference is that after 5 days growth, small halos (turbid areas) appear around the clear plaque center.  This indicates that lysogenic phage may be at the periphery of the plaque after the extended period of propagation.  (The A phage also developed a similar morphology after 5 days growth). 

CP1-03-42 B (assistant: Genevieve) was a plaque from the 81st entrance of central park.  When first plated, CP1-03-42 had 2 plaques, see Genevieve's web-page.  42 B produced small, lytic plaques after about 2 days of incubation.