Near Infrared Dye Distribution in a Nude Mouse

Biodistribution studies are critical in the investigation of novel pharmacological agents, yielding vital information about tissue distribution of drug formulations. A biodistribution study was conducted using a near infrared (NIR) dye conjugated to an antibody, highlighting the capabilities of whole animal imaging using the iBox Explorer² Imaging Microscope (UVP, LLC). The NIR DyLight (Thermo Fisher Scientific) was selected because its physico-chemical properties to facilitate immediate labelling of amine-containing molecules (e.g., antibodies) due to presence of NHS ester reactive group. An Anti-Carcino Embronic Antigen (CEA) antibody was selected as the conjugated protein due to high expression of CEA in certain cancer cell lines. A dose of the conjugate was administered in an anesthetised animal and distribution of dye monitored via NIR fluorescence imaging using the iBox Explorer². Qualitative and quantitative data analysis revealed a predilection of conjugate accumulation within the liver, sites of trauma and neck lymph nodes of a nude, non-tumour bearing mouse.

“Use of Dylight near infrared (NIR) dyes greatly expands the breadth of applications that the iBox Explorer² can support by tapping into the wavelengths currently out of reach of standard fluorescent proteins. Through these NIR dyes we can explore deep within the mouse model and capture both qualitative and quantitative biodistribution data,” said Tony Sanchez, UVP's Life Scientist.

The iBox Explorer² Imaging Microscope is an ideal system for imaging distribution of fluorescent markers within small animals for pre-clinical experimental protocols. The wide-angle lens and macro to micro imaging capabilities allow imaging of a whole animal down to individual cells. The cooled, scientific grade CCD camera rapidly captures crisp, publication quality images. A bright xenon arc lamp provides intense excitation light from the visible to NIR range, accommodating a host of in vivo studies and fluorescent markers. An application-specific filter set can be tailored for imaging virtually any pre-clinical fluorescence study.

Learn more about the iBox Explorer or read the full application note by clicking here.