Begin with nerve cells cultured in a cell differentiation medium.
Add gold nanorods into the medium.
Incubate to allow the cell to engulf the nanorod through a process called endocytosis.
Stimulate the nanorods with a laser.
The laser beam excites the surface electrons on the nanorod. The excited electrons then return to the ground state, releasing heat energy.
This heat stimulates the nerve cells to produce projections supported by a specific cytoskeletal protein called βIII-tubulin.
Remove the spent medium.
Fix the cells. Add a suitable detergent to permeabilize the membrane.
Add a blocking agent to prevent the non-specific binding of antibodies.
Label the cells with primary antibodies that target the βIII-tubulin.
Add fluorescently tagged secondary antibodies that interact with the primary antibodies.
Stain the nucleus with a blue fluorescent dye.
Using epifluorescence microscopy, observe red-colored cells with blue nuclei.
Elongated projections of the cell indicate nerve cell differentiation.