5 replies to this topic

[Omnimax]

Hi all,

I want to resuspend colonies from a mixed culture (environmental, no strains) that I have on a plate (M9 agar) and respread it on a new plate to do a little comparison on how well they will grow on different solid media. Problem is I am not sure how much (both in volume and OD) would normally be ok for spreading on a plate in order to avoid a mess of growth or an empty plate. Is there a range of "suitable" ODs for plating?

Thanks in advance,
Omni

[phage434]

OD 1 is very approximately 10^9 cells/ml (varying a lot by species and medium, and phase of moon).  You probably don't want more than a thousand cells on your plate, so you want to dilute 10^5 (adjust for measured OD) and then plate 100 ul.  You'll likely hit the right place if you did this with 10^4, 10^5, and 10^6 dilutions of an OD 1 culture.

[Omnimax]

Thanks a lot! I'll try this tomorrow and see how it works out.

[pito]

THe use of OD is something that is being misused by many.
I would advise you to check the attachements.
Try to understand it , if you do, it will make everything a lot easier and you would not make mistakes like so many others (even in published papers) do.

Attached Files

•  Wachstumsversuch.pdf   302.69K   102 downloads
•  MR13286.pdf   419.52K   138 downloads

[lyok]

phage434, on 23 August 2012 - 08:13 AM, said:

OD 1 is very approximately 10^9 cells/ml (varying a lot by species and medium, and phase of moon).  You probably don't want more than a thousand cells on your plate, so you want to dilute 10^5 (adjust for measured OD) and then plate 100 ul.  You'll likely hit the right place if you did this with 10^4, 10^5, and 10^6 dilutions of an OD 1 culture.

Phase of moon?
uh?

[phage434]

Phase of moon indicating unknown factors that are affecting your experiment.  A joke.  I hope.