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5. RESULTS spheroid after incubation of the photo-sensitizer prior to and 
after exposure to light irradiation. A view of a three- 
dimensional reconstruction of the fluorescent cells of Fig. 2b 
is given in Fig. 3. 
. Tumor spheroids present strikingly fluorescent nuclei 
after TPPS incubation and subsequent illumination. Fig. 2a 
and Fig. 2b show identical parts of a slice of a tumor 
   
figure 2a: Figure 2b: 
Partial view of an image slice from a tumor Partial view of the same tumor spheroid after 
spheroid with photo-sensitizer (TPPS) prior to light activation. Reacting cells present intense 
light activation (Magnification: 25%). fluorescence (Magnification: 40x). 
  
Figure3: 
Partial view of 3D-reconstructed fluorescent part of 
the tumor spheroid of Fig. 2b (20 slices 512 * 512 
pixels).