Strange artifact in confocal Z-stack

Posted by lechristophe on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Strange-artifact-in-confocal-Z-stack-tp593216.html

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Dear all,

One of my colleagues brought me a Z-stack today that has a circular
pattern superimposed on his sample. It is taken with a Leica SPE
confocal, pinhole at 1 Airy unit, I guess the Z step is about 0.2 µm.
If you go down the stack trough the cell toward the glass (cells on
glass coverslip observed on an upright microscope), you see a circular
ring halo appearing that lowers in radius up to a circular spot at the
center of the field. A picture is worth a thousand words, so please
check the problem here :

http://ftp.espci.fr/incoming/christo/Montage.jpg

I've seen reflections from the coverslip before as a high background
fluorescence appearing when you reach the glass surface, but I wonder
if this is reflection or a defect in the objective, or something else.
Sis anyone have a similar problem ?

Thanks a lot for your help,

Christophe



Christophe Leterrier

Postdoc
INSERM UMR641 Neurobiology of ionic channels
IFR Jean Roche - Mediterranee University
Marseille, France