## Serial Dilutions

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sweetdaisy186
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### Serial Dilutions

Hey guys!

We learned about Serial dilutions today and I don't understand it at all. We have to answer the following question:

What is the dilution factor if you add 2ml of a culture to 4mls of media?

How do I go about solving this problem? It seems like there is no pattern when answering questions about serial dilutions. Any hints would be greatly appreciated.

Thanks

vodka
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Joined: Wed Sep 06, 2006 7:17 am
9+1=10 is 10-1 dilution
9+1/10=10x10 or 10-2 dilution
similarly,
99+1=10-2 dilution
99+1/10=10-3 dilution

do u get it??

mkwaje
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dilution is simply = amt of diluent/total volume

ex. add 2ml culture to 4 ml media

2ml / 2ml + 4ml
or
2/6 <--- this is the dilution

dilution factor is simply the reciprocal of the dilution.. thus...

6/2 <---- dilution factor

you can convert it to scientific notation, but that's the basic way on how to solve it.. not all dilutions come in 1/10 and 1/100 so just remember this example. I hope this helps. good luck.

sdekivit
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mkwaje wrote:dilution is simply = amt of diluent/total volume

2/6 <--- this is the dilution

6/2 <---- dilution factor

Thus dilution factor = total volume / original volume

sdekivit
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mkwaje wrote:dilution is simply = amt of diluent/total volume

2/6 <--- this is the dilution

6/2 <---- dilution factor

Thus dilution factor = total volume / original volume before dilution

mkwaje
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Location: Philippines
Yes, that's another way of putting it sdekivit, but the results should be the same. But in my experience using the reciprocal of the dilution is much easier for students than computing it again. Thus, for example,

dilution is 1 x 10-2 , then the dilution factor is 1 x 102

and besides, if no volume of sample nor diluents are given, just the dilutions, then you would have a hard time determining the dilution factor.

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