Dye phosphoramidite stains
Richard T. Pon (rtpon@ucalgary.ca)
Fri, 23 Jul 1999 09:48:59 -0600
Hi
We are having a problem with stains from TET and HEX dye
phosphoramidites inside the column outlet lines on our PE/ABD 394 DNA
synthesizers. The problem is very curious because the dark pink stain or
deposit only occurs on the outlet tubing coming from the column. It is
also not even, the stain is most intense closest to the column outlet
and gradually thins out, until by the time it reaches the upper column
valve block, it is completely gone. The synthesizers are all working
fine and there doesn't seem to be any reagent delivery problems which
would cause incomplete washing after the dye labeling cycle.
We have been unable to rinse or clean the stain out of the lines by
using any of the DNA synthesis solvents or reagents or by removing the
lines and manually washing with water, ethanol, or acetone. Washing with
detritylation reagent causes the color to disappear, due to a pH effect,
but it returns when the acid is flushed away. The dye phosphoramidite is
clear and colorless and the inlet line to the column is not stained at
all. Lately, this problem seems to be getting worse and we have been
replacing the tubing on the synthesizer.
Has anyone observed this problem or have any idea what causes it?
--
Richard T. Pon, Director, University Core DNA Services
The University of Calgary, 3350 Hospital Drive N.W., Calgary, AB Canada,
T2N 4N1
Tel: Lab. (403) 220-4277; Office (403) 220-4225. Fax: (403) 283-4907
Please direct DNA synthesis or sequencing orders to
DNALAB@acs.ucalgary.ca