AUTORADIOGRAPHY

Autoradiography remains the gold standard for measuring in vivo biodistribution of radiolabeled molecules. This imaging technique requires tissue sectioning and imaging on film or phosphor screen. A cryostat (CM 1850, Leica) operated and maintained by CMGI staff is available for sectioning frozen tissue. Tissue samples are fixed and frozen in O.C.T. (Tissue-Tek, USA) by liquid nitrogen, cryogen spray, or a dry ice slurry. The microtome allows sectioning in thicknesses from 1-60 µm in increments of 1 µm (1-10 µm), 2 µm (10-20 µm) and 5 µm (20-60 µm). Maximum specimen size is 55 mm, which allows longitudinal sectioning of a whole mouse (up to approximately 25 g). Protocols for autoradiography, histological staining (H&E) and immunohistochemistry are available.

Phosphor Imager: Autoradiographic specimen imaging is performed with storage phosphor screens, rather than film, using a STORM 680 Phosphor Imager (GE Healthcare; formerly Amersham Biosciences). Two phosphor screens (35 x 43 cm) with an intrinsic resolution of 50 µm are available. ImageQuant software provides qualitative and quantitative data analysis.