The Optical Imaging Core located in the Animal Facility SA-443 utilizes the Xenogen® IVIS system. The Xenogen® IVIS imaging system allows the detection of light-emitting cells within a living organism. This represents a significant advance in that the presence of cells of interest can be ascertained without sacrificing an animal. The system comprises a light-tight imaging chamber, a high-sensitivity cooled charge coupled device (CCD) camera, a cooling system for the camera, and proprietary software that controls all of the system components. Access to the system is by login of registered users, the list of which is maintained by Mary Rusckowski, Ph.D., Department of Radiology, S6-315.
Email: Mary.Rusckowski@umassmed.edu. Phone: 508-856-6972.
The imaging system has the ability todetect 2 types of light - visible light generated by cleavage of the substrate luciferin by the enzyme luciferase, and fluorescent light emitted from molecules such as green fluorescent protein,red fluorescent protein, Cy3, and Cy5. Thus, cells (or introduced microorganisms) within an animal that are modified to express these proteins can be detected using this imaging system. Animals to be imaged are anesthetized, placed inside the imaging chamber, and the imaged acquired. The image acquisition time for each sample is very short (usually 1-3 minutes) and therefore this system can be used as a high-throughput screening method, in contrast to other imaging modalities such as MRI, CT, or PET. Additionally, no radioactive materials are used and animals can be imaged repeatedly over an extended period of time. Thus, this imaging system is a great complement to these other imaging modalities. In addition, the equipment is user friendly and does not require the presence of a dedicated operator.
The imaging system is currently being used for in vivo studies to monitor tumor development and progression, and additional studies to identify the presence of pathogenic microorganisms within mice. In current tumor studies, cells modified to express luciferase are introduced into the pancreas or liver during surgical procedures. At defined time points after transplantation, animals are imaged to identify the presence of developing tumors. The amount of light emitted is proportional to the number of light-emitting cells. Thus, the growth of the tumors can be determined by observing the increase in light emission. Importantly, the spread of tumors to distant sites such as the lungs (metastasis) can be identified by the presence of light emission from these sites. Significantly, early stage primary and metastatic lesions can be readily observed due the sensitivity of the imaging system.
Rate fee is $44 per hour.