streak to extinction vs quadrant streaking

[DDS19841984]

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Does anyone know the difference between streak to extinction vs quadrant streaking. Why would you use one over the other?

Thanks

 

[sciencegod]

is this a math question?

 

[lhtran07]

In microbiology? Are you referring to when you streak the agar plates?

 

[whateveryoulike]

Does anyone know the difference between streak to extinction vs quadrant streaking. Why would you use one over the other?

Thanks

quadrant streaking is done to isolate different colonies of microbes. after each quadrant you flame your loop to kill any microbes still on it and then pull from a small portion of the previous quadrant. each successive quadrant will have a smaller count until the 4th and final which should be diluted enough (if you did the quadrants properly and didnt stab the crap out of a slant to get your sample) to leave isolated colonies. if done properly, the 4th quadrant will only have isolated colonies where 1 microbe dominates. this is with the assumption that if 2 microbes of different species are left by the loop on the same spot that one will be at an advantage to the other and out compete it before you check the plate again.

streak to extinction: ive never heard of this.

ps - what does any of this have to do with the DAT? you will not get anything like this on your test