NIH 3T3 fibroblasts stained for Filamentous-actin

Phalloidin Alexa Fluor 488 nmA. G. Sostarecz, P.A. Janmey, data not published

Alexa Fluor - Fluorescein

Phalloidin Alexa Fluor 488 nm

blue green

E = hc λLonger wavelength; lower energy

A. G. Sostarecz, P.A. Janmey, data not published

Courtesy of Invitrogen website

http://probes.invitrogen.com/resources/education/tutorials/1Introduction/player.html

21

0 µm

x 1

70 µ

m

NIH 3T3fibroblasts

labeled with fluorescent TR- PIP2

-

- -

A. G. Sostarecz, P.A. Janmey, data not published

589 nm 615 nm

Texas Red Fluorophoregreen 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

purple blue green redA. 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 prismQ = quarter-wave plate compensator

632.8 nm

S = sample (reflects incident light)A = analyzer prismD = light detector