We often have questions from customers regarding which diet to choose when their experiments require fluorescence optical imaging of a live animal. The common complaint is that a grain-based diet produces background fluorescence which interferes with the experiment. This background fluorescence occurs in part because of the chlorophyll which is found in some of the diet ingredients such as alfalfa, but which also can also be found in other ingredients.
In order to avoid this issue, we recommend that the researcher switch to a purified diet when they are planning on conducting any fluorescence imaging experiments. The animals will need to be on the purified diet approximately 3-7 days prior to the imaging in order to eliminate the background fluorescence caused by the grain-based diet. For growing animals, we recommend using AIN-93G (57W5; 7597); for mature animals, we recommend using AIN-93M (58M1; 7603).
The AIN-76A purified diet is the predecessor to the AIN-93 diets, and is also a good choice for an imaging diet. The AIN-93 diets are slightly more updated than the AIN-76A, though researchers still use the AIN-76A successfully.
A paper by Bhaumik et. al was published in 2007 regarding this topic and can be found in Lab Animal 36(8):40-43, "Strategies to minimize background autofluorescence in live mice during noninvasive fluorescence optical imaging".
Please contact us for information regarding this topic.