Table 1.

Comparison of different modalities used for bone research.

Modalities	Advantages	Disadvantages
Multi-photon microscopy (MPM)	√ Efficient light detection √ Reduced phototoxicity √ Penetrates deeper into tissues √ Detection of bone by second harmonic generation (SHG)	√ Higher cost √ Artifacts caused by autofluorescence √ Difficult to image more than four colors
Confocal microscopy	√ Easy to perform simultaneous, multicolor imaging √ High spatial and temporal resolutions	√ High phototoxicity and photobleaching √ Not suitable for thick tissues because of light scattering √ Artifacts caused by autofluorescence
MicroCT	√ Three-dimensional visualization of bone architecture √ Rapid	√ No cellular information √ No molecular information
Histochemistry	√ Inexpensive √ Highly specific for individual molecules	√ No vital cell information √ Enzymatic stains cannot be easily combined