Optical imaging is a fast, sensitive, and cost effective way to image and track molecules in small animals. There are two main types of optical imaging:
Bioluminescent imaging requires genetic alteration of cells with a reporter gene (e.g. luciferase). After injection of a substrate such as luciferin, substrate oxidation occurs and emitted photons can be detected by a camera.
Fluorescent imaging is able to use native, unaltered cells for the visualization of molecular events in the animal. A fluorescently labeled targeting agent (peptide, protein, cell, etc.) is injected into the animal, where it will either be cleared from the animal’s circulation over time or retained by binding to a specific target. Upon excitation with a light source, the fluorescent dye will emit photons that are collected by a sensitive detector.
