Cranial Window-based Intravital Imaging in a Mouse Model: An Imaging Technique to Study the Behavior of Pre-injected Cancer Cells in the Brain of a Murine Model

Intravital imaging through optical imaging windows facilitates high-resolution tracking of individual cells to study their behavior in the native microenvironment in a live animal.

To begin, take an anesthetized mouse with its brain pre-injected with cancer cells and having an implanted cranial window fit inside a metal ring. The cancer cells express nuclear fluorescent proteins. 

Position the mouse, face up, in an imaging box. The magnetic holder in the imaging box helps secure the implanted cranial window.

Now, transfer the imaging box inside the environmentally controlled imaging chamber of an inverted microscope to analyze the behavior of cancer cells in the brain.

Under multiphoton mode, set the laser to a suitable wavelength. Focus on the tumor region to detect the fluorescence from cancer cells. 

Define a z-stack for each position to acquire multiple intravital images of cancer cells in different optical planes.

This step enables the capture of a significant proportion of cancer cells in the tumor microenvironment without affecting cell resolution.

Subsequently, acquire images from different positions of the tumor for an extended duration.

Tracking the path of cancer cells in different optical planes helps determine individual tumor cell migration using suitable software.