Ways of Studying Cells A. Visualization of Cells

Ways of Studying Cells A. Visualization of Cells

BSCI 420 Advanced Cell Biology Sept 11, 2002

“Any nation that does not honor its heroes will not long endure.” -Abraham Lincoln

(In honor of those who died 9/11/2001 and those injured in searching the rubble in the aftermath)

Resolving Power

Bright-fieldlight microscope

Resolution depends on the Numerical Aperture

Types of LM: A) Bright field B) Phase contrast

Types of LM: C) Diff. Interference Contrast

D) Dark field

Bright field microscopy of stained section of kidney tubules

Bright field vs. Phase contrast

Constructive and destructive interference of light

Fluorescence Microscope

Fluorescence image of a cell in mitosis labeled w 3 tags:Green: fluorescein-labeled anti-tubulin (MTS)Red: anti-centromereproteinBlue: DAPI(DNA)

Indirect Immunocytochemistry

Excitation and Emission wave-lengths

Note emission w-l is always > thanexcitation w-l.So they have lost energy(Energy = 1/wave-length

Immunofluorescence of individual MTs

Images of Conventional (A) vs Confocal (B) Fluorescence

(Drosophila embryo stained w fluorescent probe against actin)

GFT tagged talin in trichrome cells of Arabidopsis

Dynamics of GFP-labeled Cajal bodies in the nucleus