Image of the Month

Image of the Month

Optical Projection Tomography

Optical projection tomography (OPT) is a new technique for three-dimensional (3D) imaging large biological samples (of the order of 1 cubic centimetre). OPT is a novel and exciting technology and represents the next generation of optical microscopy. It is particularly suited to study fundamental biological processes using light emitted from inside the organ, via optical fluorescence. The main advantage of this new imaging modality is that it avoids the need to physically section the sample. Furthermore, OPT is able to take advantage of fluorescent dyes, and three different wavelength channels can be used. This allows the observation of the autofluorescence of the tissue (to inform on tissue structure), alongside the mapping of gene and protein expression. Our principal aim is to use the OPT scanner installed in CABI for cancer research, using particular fluorophores to stain tumors and study their vasculature.


How does OPT work?

The sample is fixed, embedded in agarose and then dehydrated to allow it to be rendered transparent, using a technique known as optical clearing. The aim of optical clearing is to replace water with 1:2 mixture of benzyl alcohol and benzyl benzoate (BABB), which makes the specimen transparent. Since the refractive index of BABB is matched to that of tissue, scattering through the sample is minimized. The specimen is then placed into the OPT device, where it is rotated to form a series of images from a range of orientations. A CCD camera registers the light transmitted from the specimen, which is focused using a series of lenses. Images are reconstructed using standard convolution filtered back-projection, and this yields a 3D volumetric representation of the specimen.


Please don’t hesitate to contact us if you would like our collaboration or assistance regarding the sample processing and the optical clearing protocol.

Please contact:
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Angela d’Esposito, PhD student

OPT management team:

Mark Lythgoe, Director of CABI

Simon Walker-Samuel, Senior Research Associate, CABI

Angela d’Esposito, PhD student, CABI

Adrien Desjardins, Senior Research Fellow and Lecturer, Medical Physics

Pete Scambler, Professor of Molecular Medicine, ICH

Morium Ali, Research Assistant, CABI

Page last modified on 11 dec 14 15:46