Serial Dilutions

About microscopic forms of life, including Bacteria, Archea, protozoans, algae and fungi. Topics relating to viruses, viroids and prions also belong here.

Moderators: Leonid, amiradm, BioTeam

Post Reply
sweetdaisy186
Garter
Garter
Posts: 1
Joined: Thu Sep 07, 2006 3:01 am

Serial Dilutions

Post by sweetdaisy186 » Thu Sep 07, 2006 3:07 am

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
Garter
Garter
Posts: 10
Joined: Wed Sep 06, 2006 7:17 am

Post by vodka » Thu Sep 07, 2006 10:16 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??

User avatar
mkwaje
Coral
Coral
Posts: 146
Joined: Mon Jul 03, 2006 2:48 am
Location: Philippines

Post by mkwaje » Wed Sep 13, 2006 1:52 am

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
King Cobra
King Cobra
Posts: 586
Joined: Sat Jul 30, 2005 7:16 pm
Location: holland
Contact:

Post by sdekivit » Sat Sep 16, 2006 4:00 pm

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
King Cobra
King Cobra
Posts: 586
Joined: Sat Jul 30, 2005 7:16 pm
Location: holland
Contact:

Post by sdekivit » Sat Sep 16, 2006 4:00 pm

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 ;)

User avatar
mkwaje
Coral
Coral
Posts: 146
Joined: Mon Jul 03, 2006 2:48 am
Location: Philippines

Post by mkwaje » Sun Sep 17, 2006 10:49 am

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.

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest