Lecture 13: techniques 2, imaging cell and tissue movement

Question 1

(mainly pictures in lecture so tried best to do flashcards, might want to look over lecture, maybe while doing flashcards)

Movement importance in development and diesease

Answer 1

-movement is an essential mechanism of development and disease
-Plays a key role during gastrulation, formation of the nervous system, organogenesis.
• Needs to be properly controlled otherwise results in disease and congenital defects.
• Understanding the mechanisms of and coordination of cell and tissue movements is a major goal of developmental biology
• Can be studied in live and fixed embryos
• Analysis is based on imaging of normal and perturbed development followed by analysis of differences in behaviour

Question 2

Imaging in biology

Answer 2

-Main used imaging methods in study of development are based on light microscopy
• Other imaging modalities
– X ray Computer tomography (CT)
– Magnetic Resonance Imaging ( MRI) – Ultrasound imaging are also used to image tissue
structure and function.
• The above methods lackcellular resolution but this may improve in the future

Question 3

Spectrum of electro-magnetic radiation (diagram in notes 4)

Answer 3

UV, visible light at 400nm then after 700 nm get infrared

-look at diagram, shows where CT, optical, ultrasound and MRI are

Question 4

Imaging

Answer 4

• Can give information about shape
• Live imaging gives information about dynamics
• Imaging can be quantitative in space and time
• Imaging is used to see items on scales from molecules to cells organs and organism

Question 5

Principle of an optical microscope

Answer 5

-have objective, tube lens and eyepiece (look slide 8!!!)

Question 6

Schematic of a modern microscope

Answer 6

• notes slide 9!!!
• field of view, object plane, marginal ray, tubus length, virtual image, intermediate image plane, loupe (eye lens), marginal ray, image plane

Question 7

Fluorescence

Answer 7

(notes slide 10)

• Jablonski diagram
• excitation-emission spectrum (absorption spectra and emission spectra)
• fluorescent molecules: conjugation, rigidty (fused aromatic rings), heteroatoms

Question 8

Fluorescence Microscopy

Answer 8

-schematic of fluorescence microscope (ocular, objective, detector, emission filter, light source, dichroic mirror, excitation filter, specimen
(notes 11)

Question 9

-Schematic of a confocal microscope

Answer 9

-detector, confocal aperture to block out-of-focus light (pin hole lets only certain amount of light so only see specific plane), laser light source, collimator, main beam splitter, scanning mirrors, objective, specimen, focal plane (12)

Question 10

Green fluorescent protein

Answer 10

• gentically encoded flurorphore
• derived from jelly fish
• great resolution
• can be used to construct fluorescent fusion proteins to label specific cells or components