[Phil Oberacker]

I just saw in this PDF link that I sent you that EDTA also causes peaks at 230 nm. However, the sample they show there is 100 mM, so 1000x concentrated compared to yours. Maybe try eluting with water and see how this looks. My money would still be on the carbs and phenolic though

[admin]

Sorry for the wrong link. I fixed it and moved all of the plant posts to this thread. Can someone tell me if in case you have set email notifications they were automatically moved too?

Cheers
Tim M

[Phil Oberacker]

Thanks, Tim! 🙂

[TimH]

Hi Mike,

Sorry we are slow to the conversation, however, I think Phil has covered off the points I would say are important. Paramount is more stringent washing of beads – I strongly suspect the 230 peak is GITC contamination; especially as you point out you see it even when there is no plant tissue at all (so this is a general bead issue, not just plant protocol). I would compare it to commercial gel extraction kits, which always produce a peak at 230, presumably because of GITC carryover in the column. I think the pertinent question is probably, what level of GITC carryover are you comfortable with? A little bit of carry over is not an issue (as in gel extraction), but too much and it can inhibit downstream enzymatic reactions. We have always managed to find a balance we are happy with.

Cheers,

TimH

 

[Hary]

Hi Mike,

Did you finally resolve the peak problem at 220-230 nm and a low ratio of 260/280?. I have the same problem when testing protocol #6.4 for Eucalyptus species.

 

Thanks

Hary

[Author]

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