Microplate Reader

Michael Irwin mirwin at tiac.net
Sat Jun 13 14:34:10 EST 1998


On Tue, 09 Jun 1998 16:58:03 -0400, " Arnold N. DuBell"
<dubell.1 at osu.edu> wrote:

>Hi,
>Our department is considering purchasing a microplate reader for a
>variety of uses.  I've looked at a number of companies' products already
>(posted on the web), but am curious if anyone has suggestions.  I know
>it probably isn't possible, but we'd like to do UV, fluorescence, and
>luminescence (although on all the instruments I've seen so far, this
>option is separate from the other two.   Is there a physical reason for
>this, or is it just market economics)?

At least in the old days, there used to be a physical reason for it.
Most absorbance readers detect with photo-diodes while the greater
sensitivity needed for fluorescence work uses photo-multiplier tubes.
To do both types of work with a PMT requires careful tuning or
light-blocking when doing one versus the other in order not to either
flood the PMT or kill sensitivity. Be certain therefore to check each
seperate set of specs closely and not pay too much heed to one set of
specs only.

I know some people are still either superstitious or very demanding to
the point that they'll prefer to use two seperate machines to maximize
abs and fluor performance. I don't know enough to say whether or not
that's still true. 

The posting about the Mol Dev machine should be clarified too. Those
wavelengths are only for absorbance. It's probably a decent abs
machine but it doesn't do fluorescence and it doesn't handle the
growing demand for multiple plate types like 48, 24, 384, etc that
some other readers do.

Good luck, Mike



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