Don,

We have used with success a laser ablation system mounted on a Zeiss
Axioplan microscope. The system is produced by Photonic Instruments.  We
have dealt with Robert Nowak at (847) 797-8825.  Robert should also be able
to answer your technical questions.

Louie Kerr

At 10:53 AM -0500 12/10/98, Donald OMalley wrote:
>Hi All,
>
>    We are trying to laser ablate neurons inside the hindbrain
>of the zebrafish and are having trouble killing some of the
>cells.  We're simply zooming (86x) in on the cells on our MRC 600
>and continuously lasing them with either the 488 line (for
>calcium green dextran) or the 568 line (for Texas Red dextran);
>using our Argon Krypton laser.
>    While this appears to kill many of the cells that we lase,
>some of the cells can be lased many times, without any apparent
>loss of cell integrity.  (i.e. we bleach the cell, but after
>waiting the cell "reappears" presumably because of dye diffusing
>back into the cell body from the axon or dendrites.)
>
>FINALLY: my question: Are there any fluorescent dyes (especially
>dextran-linked dyes) that produce more photodamage,
>photoxicity when lased at 488 or 568 nm?  (We don't
>have a way to use UV on our set up).  We may just have to get a
>more powerful laser and pipe it into our light path to more efficiently
>kill cells, but we're already killing a good fraction of them, so a
>more damaging dye would be a simpler solution.  Thanks for any tips; any
>references on how lasing cells actually kills them would also be
>greatly appreciated.
>
>Don
>


Louie Kerr
Research and Education Support Coordinator
Marine Biological Laboratory
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508-540-6902 (FAX)

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