In vivo bioluminescent imaging (BLI): noninvasive visualization and interrogation of biological processes in living animals

Abstract

In vivo bioluminescent imaging (BLI) is increasingly being utilized as a method for modern biological research. This process, which involves the noninvasive interrogation of living animals using light emitted from luciferase-expressing bioreporter cells, has been applied to study a wide range of biomolecular functions such as gene function, drug discovery and development, cellular trafficking, protein-protein interactions, and especially tumorigenesis, cancer treatment, and disease progression. This article will review the various bioreporter/biosensor integrations of BLI and discuss how BLI is being applied towards a new visual understanding of biological processes within the living organism.

Keywords: BLI; Luc; Lux; bacterial luciferase; bioluminescent imaging; firefly luciferase.

Figure 1.

In vivo comparison of the FLuc and Lux reporter systems in a mouse model. Following subcutaneous injection of both (A) FLuc-tagged cells and luciferin or (B) Lux-tagged cells alone, the subject is imaged to determine the size and placement of the target cellular population within the animal. Similar experiments can be performed for (C) FLuc or (D) Lux-tagged cells following intraperitoneal injection. Although the average radiance of the FLuc cells is greater than that of Lux cells (note inset scale values), the low background detection ofsmall animal BLI allows for similar localization of cellular populations within the subject.