Immunofluorescence

The green fluorescence represents the location in the cell of a protein found in the Golgi apparatus in all pictures.
The red fluorescence:
1) in the top picture represents the location of the cytoskeleton of the cell and specifically microtubules (anti-β-tubulin used)
2) Middle picture represents the location of late endosomes and lysosomes in the cell (anti-CD63 used)
3) in the bottom picture represents the location of the endoplasmic reticulum (E.R.) in the cell (anti-PDI used).

The cells used were COS-7 (African green monkey SV40 transformed kidney fibroblasts) and confocal microscopy was used to view the fluorescence emitted by the fluorophore of different color conjugated to secondary antibodies.