In several research projects in our department we use a confocal laserscanning microscope (CLSM) as the instrument of choice for the analysis of brain sections. There are many good reasons to use the CLSM. To list a few:

 

  • If one needs to determine with a high level of confidence whether there exists colocalization of substances inside small structures

shown here: double-labeling in the hippocampus of the rat. Immunofluorescence staining of calbindin (red, 594 nm fluorochrome) and calretinin (green, 488nm fluorochrome). The orange and yellow neurons contain both proteins.

 

  • if one needs the highest resolution possible with a light microscope

    shown here: double-labeling in the temporal cortex of the rat. Immunofluorescence staining of parvalbumin (red, 633 nm fluorochrome) and axons labeled with biotinylated dextran amine (green, 488nm fluorochrome). The swellings on the fibers indicate axon terminals.

  • if one wants to do 3D reconstruction

    shown here: double-labeling in the basal ganglia of the rat. Staining of a cell which contains a tracer, biotinylated dextran amine (red, 594 nm fluorochrome) and a cell immunostained for choline acetyltransferase (green, 488nm fluorochrome). Screen capture of a 3D reconstruction.

  • Just for making nice detailed pictures

    shown here: GFP-expressing granule cells in the dentate gyrus of a transgene mouse. GFP expression is also present in fibers and in the mossy fiber terminals which are the granule cells' output stations. (excitation at 488 nm). Extended focus image.