PCR product sequencing BD v3.1 - Help in removal of residues (Apr/27/2004 )

I have been using BigDye V3.1 to do my sequencing. There is always a region at abt 190bp that i cant call out my base reading. I'm wondering if it is caused by ethanol contamination. what is the best way to preciptate my product after the BigDye Terminator Reaction?

Hi! this is the protocol I use to precipitate DNA with etanol and EDTA (it works for the BigDye 3.1)

20 microl. of your sequencing reaction plus 5 microl. of 125 mM EDTA
Add 60 microl. of etanol 100%
Vortex
RT 15 minutes
centrifugue 20 minutes at 14.000 rpm 4ºC
Remove the etanol
Add 200 microl. of etanol 70%
centrifugue 2 minutes at 14.000 rpm 4ºC ( make this 2 times more)
And then remove all the etanol, make sure that there's no etanol.

I'll hope it works for you!!
Bye!