Flowgram signals to quality score

[mbakker]

Can anyone explain how the raw flowgram signals are converted into quality scores for the 454 GSFLX system? I'm trying to compare two processing methods, and am running into trouble with each screening for quality based on different criteria (one based on flowgram signal, the other based on quality score).
Thanks!

[flxlex]

From the manual:

"The signal flowgrams of the reads are basecalled and quality scores for each base are calculated based on the signal properties relative to the statistical distributions of the Control DNA fragment signals."

Does that help?

[TSR]

I would also love an explanation of the 454 quality scores.

I think there is an error in the original definition of 454 quality scores, as described here: http://seqanswers.com/forums/showthread.php?p=50237

Cheers,
T