Fluorometer: to buy or not?
Christopher T. Cole
colect at caa.mrs.umn.edu
Mon Feb 12 17:24:25 EST 1996
On 9 Feb 1996 15:13:37 GMT,
Stephen Marcus Lane <smlane at unity.ncsu.edu> wrote:
>I'm considering whether or not to get a fluorometer for the
>quantification of DNA (and RNA, if possible). I've only
>looked at the Hoefer DyNA Quant 200 so far, and it looks
>like the price will be around $3000 for the meter and
>I really want to have a more accurate and sensitive way
>of quantifying DNA than spectrophotometry in a 1 mL cuvette.
>I just don't trust it. The DNA samples that I want to quantify
>run the gamut; PCR products, cell preps, other polymerase/ligase
>/nuclease reactions, all in various forms of purification,
>by EtOH or phenol/CHCl3 or agarose/acrylamide gel elution
>(yes, I'm trying out a lot of different techniques).
>I know mononucleotides, proteins, and phenol pretty much render
>an A260 measurement worthless if they're present in even small
>amounts. And I think the same is true for agarose and
>acrylamide (?). So I don't like relying on spectrophotometry.
>I haven't tried using a 4-variable equation at 230, 260, 280,
>and 320 nm. Can anyone offer info on the improvement this
>offers over just A260 (and A260/A280) for possibly-contaminated
>One final thing; I've just started checking out fluorometers.
>I can't seem to find anything in the catalogs about what
>contaminants can throw off the reading. Is the Hoechst assay
>specific enough that the above contaminants (monont's, proteins,
>gel debris) aren't detected?
>Thanks for any help, Steve
>-- Steve Lane <steve at ncsu.edu> -------------------------------
We got a Dyna Quant 200 last summer and have been very happy with it. It
is useful for much smaller quantities and/or concentrations than we can
handle in 1 or 2 ml cuvettes with UV. We do not use the capillary
adapters. Most of our readings are in the 5 to 200 ng/ml range. I put the
device in the hands of undergrads and leave them alone with it, reliably.
More information about the Methods