title: Investigation of influences of the paraformaldehyde fixation and paraffin embedding removal process on refractive indices and scattering properties of epithelial cells.
abstract: The scattering properties and refractive indices (RI) of tissue are important parameters in tissue optics. These parameters can be determined from quantitative phase images of thin slices of tissue blocks. However, the changes in RI and structure of cells due to fixation and paraffin embedding might result in inaccuracies in the estimation of the scattering properties of tissue. In this study, three-dimensional RI distributions of cells were measured using digital holographic microtomography to obtain total scattering cross sections (TSCS) of the cells based on the first-order Born approximation. We investigated the slight loss of dry mass and drastic shrinkage of cells due to paraformaldehyde fixation and paraffin embedding removal processes. We propose a method to compensate for the correlated changes in volume and RI of cells. The results demonstrate that the TSCS of live cells can be estimated using restored cells. The percentage deviation of the TSCS between restored cells and live cells was only −8%. Spatially resolved RI and scattering coefficients of unprocessed oral epithelium ranged from 1.35 to 1.39 and from 100 to 450 cm−1, respectively, estimated from paraffinembedded oral epithelial tissue after restoration of RI and volume.
authors: National Taiwan University, Institute of Biomedical Electronics and Bioinformatics, Taipei 10617, Taiwan.
authors: Jing-Wei
authors: JW
authors: Su
authors: National Taiwan University, Institute of Biomedical Electronics and Bioinformatics, Taipei 10617, Taiwan.
authors: Wei-Chen
authors: WC
authors: Hsu
authors: National Taiwan University Hospital, Department of Dermatology, Taipei 10617, Taiwan.
authors: Jeng-Wei
authors: JW
authors: Tjiu
authors: National Taiwan University Hospital, Department of Dentistry, Taipei 10617, Taiwan.
authors: Chun-Pin
authors: CP
authors: Chiang
authors: National Taiwan University, Department of Animal Science and Technology, Taipei 10617, Taiwan.
authors: Chao-Wei
authors: CW
authors: Huang
authors: National Taiwan University, Institute of Biomedical Electronics and Bioinformatics, Taipei 10617, TaiwaneNational Taiwan University, Department of Electrical Engineering, Taipei 10617, TaiwanfNational Taiwan University, Molecular Imaging Center, Taipei 10.
authors: Kung-Bin
authors: KB
authors: Sung
mesh_terms: D004847:Epithelial Cells / Q000737:chemistry / Q000166:cytology; D005557:Formaldehyde / Q000737:chemistry*; D006367:HeLa Cells; D006801:Humans; D008027:Light; D009061:Mouth Mucosa / Q000166:cytology; D061848:Optical Imaging; D016612:Paraffin Embedding; D011108:Polymers / Q000737:chemistry*; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation; D016707:Tissue Fixation
chemical_list: D011108:Polymers; D005557:Formaldehyde; C003043:paraform