Help needed/urgent

Jonathan B. Marder MARDER at agri.huji.ac.il
Sun Feb 27 02:22:04 EST 1994


In article <199402220409.UAA01431 at net.bio.net> GOVINDJEE at C.SCS.UIUC.EDU ("GOVINDJEE") writes:

[...]
>There is another question.I have been trying to see if I can demonstrate
>chlorophyll fluorescence of leaves (perhaps, with or without DCMU or
>atrazine) visually to students without the use of sophisticated
>instruments. I remember seeing it myself once (perhaps, it was
>Dr. Don Miles who showed it--I am not so sure). I have tried it myself
>recently with UV light excitation of light-colored Coleus leaf, but
>did not see much to convince me. I also tried excitation with blue
>light (free of red light), but did not see it.We are told that H.Kautsky
>observed it with his eyes in a dark-adapted room. If anyone has
>any experience on this problem, I would appreciate hearing.
>In return of the above help, I will be delighted to send you any lab.
>description I produce if you will please give me your address.

I have done this using a long-UV lamp (the sort used to view Ethidium
Bromide stained gels Ethidium-Bromide).  I got it to work with DCMU-inhibited
duckweed.  However, it is a bit tricky and you have to get used to doing it.

I recently tried to set it up again (not on duckweed) as a demonstration, but
failed!  Perhaps the lamp I had wasn't up to it.

Another trick you could try is to sandwich  leaves between red and blue
filters which have no overlapping transmission.  Using a resonable strong
white light-source, you should be able to show that the filters alone
transmit no light, yet you can see the leaf via its fluorescence.

I hope this is of some help!
__
Jonathan B. Marder                 '
Department of Agricultural Botany  |     Internet: MARDER at AGRI.HUJI.AC.IL
The Hebrew University of Jerusalem | /\/ Bitnet:   MARDER at HUJIAGRI
Faculty of Agriculture             |/  \ Phone:    (08 or +9728) 481918
P.O.Box 12, Rehovot 76100, ISRAEL  /     Fax:      (08 or +9728) 467763



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