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Fig. 7. Confocal microscopy of mixed CEACAM1-transfected and untransfected MDCK
cells. Untransfected MDCK cells were mixed 50:50 with either
CEACAM1-L-transfected or CEACAM1-S-transfected MDCK cells and grown to
confluence on permeable filters. The cells were treated with or without
hyperosmotic sucrose, fixed with 3% paraformaldehyde and permeabilized by
methanol for 2 minutes at room temperature. Some cultures were stained with
anti-CEACAM1 mAb 5.4/Alexa488-conjugated secondary antibodies (green colour),
and some cultures were double-stained with anti-CEACAM1
CC16/Alexa
546-conjugated secondary antibodies (red colour) and
antioccludin/Alexa488-conjugated secondary antibodies (green colour). The
horizontal lines in the xy-composites indicate the plane for the
z-reconstructions. Note that lateral expression of CEACAM1-L is only found in
the borders between CEACAM1-L expressing cells but not in the borders between
CEACAM1-L expressing cells and untransfected cells. CEACAM1-S was not stained
by mAb 5.4. Bars: 20 µm.