In Vivo Imaging
Both the Ivis Spectrum and the VisualSonics imaging machines are able to obtain good signal-to-noise data, but there are some techniques that can and do improve this.
Shaving / depilation
Both bioluminescence and fluorescence signals lose energy as they are emitted from the subject, although fluorescence loses a much higher percentage.
To combat this loss of signal, the animals may be shaved or depilated by other means over the area of interest. Animal hair is a potent quencher of fluorescent signal, and its removal is important in order to give good data acquisition.
CTAC recommends the use of a standard beard trimmer or similar hair clipper, to cut down the hair to 2-3 mm thick. This should then be followed with the application of an over the counter hair removal product such as Nair™ or similar. Care should be taken to avoid the Nair™ having direct skin contact for more than 5 minutes. This is critical to avoid chemical mediated burning.
Unfortunately, most commercially produced rodent chow is based on alfalfa products, which cause large quantities of autofluoresence in the animals’ center mass. Therefore, the Core recommends that your animals are fed an alfalfa-free diet for 1 (one) week prior to imaging. The type of food recommended is Harlan Teklad # 2018S rodent chow. ACS now provides this diet as their standard diet for mice.