Team:ArtScienceBangalore/Notebook/Imaging

From 2009.igem.org

There are many microscopes available to scientists. There are so many varieties, primarily because scientist require different resolutions for different cells or (whatever else they might want to look at really close up)

Brain.jpg

Brain cell of a fruitfly under a confocal microscope.

There are point/line/disc scanning microscopes

Generally,the software to operate microscopes are sold with the microscope. Some of them are 'CellQuest Pro' etc.

-Without optics, there is no biology

250nm- Wide field microscope 100nm-TIRF 50nm- 20nm-STED 1nm-AFM <1nm-Electron microscope -This is the only electron-based microscope; rest are photon-based: Costs Rs 3 crore,is manufactured in hundreds per year only in select countries like Japan and Germany.

Some basics of microscopy:

1.Pixel size in case of magnification should not exceed Theoritical resolution/2.3 2.Dwell time of laser= Time spent on one pixel to read it 3.Voxel- A 3-D pixel in microscopy 4.Resolution is the smallest distance possible between two objects before they look like one.

One of the microscopes that we saw closely was a Confocal microscope. The specimen we viewed was a fixed cell of a fruit fly's brain.
We viewed it under red and green laser as well as with its own florescence.
We also saw a Transmission Electron Microscope and an Atomic Force microscope.

Flow Cytometry

Its a method that helps scientists count, sort and analyse particles that are too small and in very large quantities.
The particles are usually in the order of 10 µm.
The machine works by forcing the cells under very high presure along a narrow stream of liquid called the sheath flow.
The Sheath flow has lasers that pass it perpendicularly.
The machine counts the particles at very high speeds by counting the disturbances in the laser beam.
By analyzing the way the lasers excite fluorescent cells, and create pulses of released photons it can sort the different particles.
The released photons will have spectral qualities that are unique to its fluorochrome.
It is necessary to know the properties of the dyes used on the particles in order to identify them.