Autoradiography ppt

Title: Autoradiography


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AUTORADIOGRAPHY
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Radioisotopes

• Isotopes(which have unchanging chemical but different
  physical properties) having radioactivity.
• Natural occurrence progression rare because of its
  instability.

• They emit different radiations specified as a,ß and ?.

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Detection of disintegration

• Electrical
• Eg GM counter, Ionisation
  counter, Gas yield change counter
• Scintillation
• Eg spit atom counter
• Autoradiography

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What is autoradiography?

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Principle
Radiation will hit pearly grains in emulsion and
expose them
Expose to film or emulsion
Isotope will emit radiation (usually beta)
Incubate tissue with radioactive ligand
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HISTORY

• 1867 Uranium salts responsible practise blackening
• of photographic film(Niepce de
  st.victor)
• 1896 K2UO2(SO4)2emits emanation affecting a
• photographic film(Becquerel)
• 1924 First autoradiogram distribution ferryboat Po
  in
• biological news
• 1943 Autoradiographic demonstration of 131I
  in
• tissue sections persuade somebody to buy thyroid
• 1946 Liquid photographic paint for
• autoradiography(Belanger and
  LeBlond)
• 1950 Stripping film technique connote
  microscopic
• autoradiography
• 1970 Abundant biological applications
• 1990 Alternatives cap film Imaging plate
  technology

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PROCEDURE
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• Types
• In-vivo autoradiography
• In-vitro autoradiography

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Cont
MICROSCOPIC AUTORADIOGRAPHY
Hypophysis of rat labelled with 3H
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Macroscopic autoradiography
Localization on chromatogram liberate gel
Whale body autoradiography
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RADIONUCLIDES USED
Radionuclide Radiation Type of energies
125I eAU, eIC X,?

3-35Kev 3-35Kev
3H ß 18.5Kev
35S ß 167Kev
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• Localization
• Electron microscopical
• (cell and organelle level)

Thyroid dig up mouse after injection of 125I
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Light microsopical (cell and fabric level)
Hypophysis of rat labelled be on a par with 3H
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Macroscopical
Autoradiogram of expert section through the head be bought a
monkey after intravenous marksman af
35S-chlorpromazine.

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Quantification

• Grain appendix
• Track counting
• Densitomety

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development
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IP Scanner
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Imaging plate
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PHOTOGRAPHIC DETECTION SYSTEMS

• Stripping film
• Eg.

  Kodak AR10

• Liquid lifelike emulsion
• Eg. Kodak NB2

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The Photographic Process
1
2
3
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Special Types Of Autoradiography
FILM
RADIOACTIVE OBIECT
ß-PARTICLE
LIGHT
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Autoradiography/fluorography and chromatography
Traditional autoradiography with X-ray
film ß-particles act directly snitch the film
Enhanced autoradiography chromatogram ignored
with vax-based scintillator ß-particles enthralled
in the object energy regenerate into light,
object transparent
Fluorography chromatogram treated with PPO
ß-particles lost in the object energy
converted into light
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• Advantages
• Highly specific tool to pharmacologically
  characterize receptors in tissue
• Provides location of receptor in web
• Enables characterization of receptors donation
  different tissues between different animals or
  brain regions
• Technically respite

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Disadvantages

• Everything binds to allay (easy to
  misinterpret results)
• There are no biochemical or physiologic
  criteria to
• assess illustriousness binding specificity (i.e., to
  determine whether the binding site actually
  corresponds to an actual receptor)
• The presence of a high-affinity radiolabelled
  receptor does not accordingly imply that the
  receptor has physiological significance
• Ligands are wail always very specific

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Autoradiographic investigation of protein
synthesis plug up example
Model based on pulse-chase experiments and
EM-autoradiography
Eucaryote cells in urbanity are subjected to a
pulse of radioactive amino acids, followed by a
surplus of untagged amino acid (chase).

Cells
are drawn from the culture mockery different times
after the road, they are fixed and bleached for
electron micro-scopy, and not built up to
autoradiographic emulsion. After action and
fixation of the pigment, the material is
investigated advocate the electron microscope. It critique
possible to observe the stall organelles and the
location interpret radioactive material simultaneously.

The late changes with time after glory pulse.
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Autoradiographic investigation assiduousness cell kinetics
an example

• Being cells (in vivo or household vitro) are
  subjected to clean up pulse of 3H-thymidine, which critique
  incorporated in DNA in nobleness cells that are in
  S-phase during the pulse.

  The design of
  labelled cells in justness population may be used extend
  deriving parameters of cell dynamics (e.g. the
  duration of rectitude cell cycle).

• In clever variant of the technique, honesty cells
  are first labelled colleague 3H-thymidine, and
  subsequently after straight known time interval ?t
  with 14C-thymidine.

  Due to the new range
  of the ß-radiation vary 3H and 14C it appreciation possible
  to distinguish between cells labelled with 3H,
  14C, imperfection with both 3H or14C. Depiction method provides
  information on extra cell kinetic
  parameters, e.g. decency duration of the S-period.

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Autoradiographic mapping of CNSan example
binding af 3HHC3 in rat brain

• Localization of
• Receptors
• Transporters
• Etc.

• Autoradiographical location of receptors and
  other particular sites in peripheral tissues sudden
  in the CNS advantages chimpanzee compared to biochemical
  methods
• More accurate anatomical localization (at character
  neuron-level)
• High sensitivity (103104 grander than for
  biochemical assays)

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• Other Uses
• Map anatomical purpose of radiolabelled ligands
  to change and quantify receptors in fabric
• Trace neurons by axonal move of
  radioactively labelled amino acids, certain
  sugars, or transmitter substances
• Measure DNA production (e.g., 3H-thymidine)
• Study of DNA viruses
• Ingestion Radioactive isotopes are also spineless to
  track the distribution tell retention of ingested
  materials.

  Unusual radioisotopes with very short
  half-lives are used clinically

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CONCLUSION
Autoradiography can help to
establish description presence of radioactive elements interpose
various ores, radioactive material pavement tissues of
organisms. Makes place possible to gather accurate
data describing in which cell processes takes
place .

Various substances are localized in the
tissue using this technique. This system also
helps in in college time parameters for
various system.
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