Internal standard vs External standard? - (Jun/07/2012 )

Hello geniuses all over the world,

Im pretty new to FCM, however, i have read alot of papers and articles relating to FCM.
The problem is that none of these article explain what internal and external standards are.
I believe that i need some sort of standard for my plant nuclei so that i know which peaks in the number/flourescence graph corresponds to which ploidy level (2C, 4C, 8C, 16C, etc.).
From what i could speculate, internal is just a number you plug in into the computer? While external is you run the known DNA content nuclei from another organism with my samples? This was quite confusing so i needed some clarification.
Also, FYI, the plant organism that i am working with is already sequenced and DNA content was already identified using FCM quite a time ago (90's i believe).
If possible, could anyone explain what these standards are and if i require them for my experiment?

Thank you for reading this and your help would be appreciated.
Pat

Taking a shot here, when I personally refer to internal controls, they are controls I (my facility) made. When I refer to external controls, they are controls I bought; 3rd party QC/STDs.

Thx for the quick reply! However, im not quite sure if thats correct...
I found a good guide book in Plant cell biology 2001, so im heading over to the library to take a look.
I'll post something if i find the answer.

Thanks alot tho for the help!

Please do! And I apologize if I steered you wrong. I'm curious now.