> That being said, in-line SEC-DLS-SLS etc is a much more powerful
> technique, but is less straight-forward, has a larger footprint and as
> has been mentioned, less-inexpensive.
Having an online SLS (or MALLS as people call it as well these days,
multi angle laser light scattering ) is indeed nice, and clearly
useful for assessing real molecular weights.
Having an online DLS (which basically is more or less the same
instrument but just capable to do an auto-correlation of the
scattering signal over time from what I know) somehow misses the point
(or do I miss the point?):
a. you want to do DLS to check polydispersity of your ready-to-
crystallize sample in various buffers, thus why online? 96-well format
is more like it.
b. if you do online DLS you need to autocorrelate the signal over a
few seconds, so you loose some of the resolution in your SEC/SLS
profile? I admit however that I am not sure how long you need to
autocorrelate the scattered intensity to evaluate if you have a single
exponential decay that would suggest a mono-disperse particle
We have looked at the possibility of one instrument doing Static, On-
line LS *and* DLS in a cuvette. Given that the MALLS is quite a
sensitive do-not-disturb-me kind of beast, I feel better we did not do
that.
Tassos
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