Re: Molecular Probes Alexa

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From:tylee <>
To:"J. A. Kiernan" <>, "Michael J. Lyon, Ph.D." <lyonm@VAX.CS.HSCSYR.EDU>
Date:Thu, 18 Mar 1999 21:59:41 -0600
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I agree with you totally about the problems of non-disclosure and I am
disgusted that companies seem to have a habit of doing this; however, upon
searching the Probes web site, I found a structure for the first 2 Alexa
dyes I looked for at and
In general, regarding why Probes keep some of their structures or
formulations a secret... it is because they can make more money that way.
For instance, companies sell dyes in high priced "kits" under a "Tradename".
The kits would be simple to reproduce if the company disclosed the nature of
the dye (that you could probably find in their catalog in a different
section for about 5% of the cost of the kit). People will pay for
Ty Lee

-----Original Message-----
From: J. A. Kiernan <>
To: Michael J. Lyon, Ph.D. <lyonm@VAX.CS.HSCSYR.EDU>
Cc: Confocal Users Group (E-mail) <>; Histonet
(E-mail) <>
Date: Thursday, March 18, 1999 6:14 PM
Subject: Re: Molecular Probes Alexa

>On Thu, 18 Mar 1999, Michael J. Lyon, Ph.D. wrote:
>> Molecular Probes has introduced a new fluorchrome, Alexa.  Has anyone
used any of the different conjugates or the new Alexa 488 signal
amplification kit for fluorescein conjugate probes?  What were your results?
MP says they are much more photostable. Any comments welcome.
>  The Molecular Probes literature does not give any indication
>  of what Alexa is - just says how good it is for everything.
>  The use of a secret substance in research cannot be justified
>  (what decent journal would publish your results?). With all
>  the fuss about reagents for diagnostic use it is also difficult
>  to imagine anyone daring to use a completely unknown labelling
>  reagent in a clinical lab. One is left wondering who Molecular
>  Probes expects the customers to be! Their catalogue is full of
>  structural formulas and other information about their other
>  fluorochromes. Why keep this one secret? Until they give some
>  simple information about their Alexa label, they cannot seriously
>  expect anyone to buy it. After all, there is no shortage of
>  fluorescent labelling compounds whose chemistry is fully disclosed
>  and discussed in textbooks and peer-reviewed journals.
> John A. Kiernan,
> Department of Anatomy & Cell Biology,
> The University of Western Ontario,
> LONDON,  Canada  N6A 5C1

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