NIH 3T3 fibroblasts stained for Filamentous-actin Phalloidin Alexa Fluor 488 nm A. G. Sostarecz, P.A. Janmey, data not published

Alexa Fluor - Fluorescein Phalloidin Alexa Fluor 488 nm bluegreen E = hc λ Longer wavelength; lower energy A. G. Sostarecz, P.A. Janmey, data not published Courtesy of Invitrogen website

210 µm x 170 µm NIH 3T3 fibroblasts labeled with fluorescent TR- PIP A. G. Sostarecz, P.A. Janmey, data not published

589 nm 615 nm Texas Red Fluorophore green red Courtesy of Invitrogen website A. G. Sostarecz, P.A. Janmey, data not published

How are we able to do simultaneous fluorescence?? A. G. Sostarecz, P.A. Janmey, A. Kennedy, data not published

purplebluegreen red A. G. Sostarecz, P.A. Janmey, A. Kennedy, data not published Courtesy of Invitrogen website

ELLIPSOMETRY Determines properties of surfaces and thin films An ellipsometer allows for the measure of the refractive index and the thickness of semi-transparent thin films. The reflection at an interface depends on the polarization of the light The transmission of light through a transparent layer changes the phase of the incoming wave depending on the refractive index of the material Reflection properties change as the thickness of a sample changes (a few Angstroms)

SET UP – Null Ellipsometer L = light source (low power HeNe laser) P = polarizing prism Q = quarter-wave plate compensator nm S = sample (reflects incident light) A = analyzer prism D = light detector