Quantification of light attenuation in optically cleared mouse brains.
Optical clearing, in combination with recently developed optical imaging techniques, enables visualization and acquisition of high-resolution, three-dimensional images of biological structures deep within the tissue. Many different approaches can be used to reduce light absorption and scattering within the tissue, but there is a paucity of research on the quantification of clearing efficacy. With the use of a custom-made spectroscopy system, we developed a way to quantify the quality of clearing in biological tissue and applied it to the mouse brain. Three clearing techniques were compared: BABB (1:2 mixture of benzyl alcohol and benzyl benzoate, also known as Murray’s clear), pBABB (peroxide BABB, a modification of BABB which includes the use of hydrogen peroxide), and passive CLARITY. We found that BABB and pBABB produced the highest degree of optical clearing. Furthermore, the approach allows regional measurement of light attenuation to be performed, and our results show that light is most attenuated in regions with high lipid content. We provide a way to choose between the multiple clearing protocols available, and it could prove useful for evaluating images that are acquired with cleared tissues.
University College London, Centre for Advanced Biomedical Imaging, 72 Huntley Street, London WC1E6DD, United Kingdom.
Angela
A
d'Esposito
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E6BT, United Kingdom.
Daniil
D
Nikitichev
University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E6BT, United Kingdom.
Adrien
A
Desjardins
University College London, Centre for Advanced Biomedical Imaging, 72 Huntley Street, London WC1E6DD, United Kingdom.
Simon
S
Walker-Samuel
University College London, Centre for Advanced Biomedical Imaging, 72 Huntley Street, London WC1E6DD, United Kingdom.
Mark F
MF
Lythgoe
D065638:Absorption, Radiation; D000818:Animals; D001921:Brain / Q000033:anatomy & histology*; D001923:Brain Chemistry; D007089:Image Enhancement / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008027:Light; D051379:Mice; D008819:Mice, Nude; D057054:Molecular Imaging / Q000379:methods*; D012542:Scattering, Radiation; D041622:Tomography, Optical / Q000379:methods*