 The possibility of generating appropriate transgenic mice is crucial for intravital microscopy studies.For example, in order to study the behavior of microglial cells in Alzheimer’s disease researchers will need to crossbreed a transgenic mouse that is a mouse model of Alzheimer’s disease with another transgenic mouse that is a mouse model for visualization of microglial cells.Cells need to produce a fluorescent protein to be visualized and this can be achieved by introducing a transgene.