Various dyes and particulate markers have been used to mark the “risk zone” in evaluating regional ischemia. Markers that have been used include Evans Blue, India Ink and Fluorescein. However, these dyes tend to rapidly migrate throughout the tissue making the risk zone difficult to identify. Fluorescent particulate markers are effective because they lodge in the capillaries and are easily visualized under fluorescent illumination. The particles are heavily loaded with dye, resulting in a very strong fluorescence that can easily be seen. They are invisible under white light, allowing the non-risk tissue to be examined for infarction. Since the dye is embedded in the interior of the particles, it does not leach out or cause indiscriminate staining.
Recommended for: Used for myocardial infarction studies and other biological research. Not to be used for instrument calibration.