3-D Reconstruction of the Rabbit Brain from Serial Histology Sections

Enrico Gratton

Physics Professor

UIUC

15 April 1999

Using two-photon excitation, the volume explored by the laser beam can be made extremely small, below a fL. In this volume, given the normal concentration of fluorophores found in biological preparation, the number of fluorescent molecules is small. Fluctuation spectroscopy provides an absolute method to quantify the number of molecules in every location of an image and the kinetics processes that change the number of molecules in that volume.