Enhanced OCT imaging of embryonic tissue with optical clearing

Optical coherence tomography (OCT) holds great promise as a routine research tool for 3-D analysis of mammalian embryos. However, despite the depth penetration afforded by this imaging modality, light attenuation in tissues imposes limitations. Here we studied the optical clearing effect of different concentrations of glycerol in mouse embryos. Depth- and time-resolved profiles for OCT signal enhancement are presented. We found that application of 50% glycerol resulted in 51.5 +/- 12.5% improvement of the OCT signal, while 25% glycerol enhanced the OCT signal by 25.2 +/- 7.3% at the depth of about 200 to 500 pm, and the glycerol permeability rate was estimated as 26.7 +/- 6 mu m/min. These results demonstrate that embryonic imaging is improved by application of glycerol as optical clearing agent.