I do not work with mice myself. Plenty of people in my lab do though. Most mice used in science are inbred laboratory mice so end up being a little different to field or pet mice. A very common strain of mice called C57BL/6 (https://en.wikipedia.org/wiki/C57BL/6).
Many people then copy and paste new genes into these mice so they glow. By putting the glowing gene into different places in the DNA, you can make specific organs glow!