Advantages And Disadvantages Of Microscopy

Optical Microscopy makes use of a light source to illuminate the sample and uses lenses to magnify the image. This system is coupled with CCD and CMOS to get digital images. Light microscope has two basic divisions, simple microscope and compound microscope.

Confocal microscopy and fluorescent microscopy, in addition to the techniques used by light microscope uses other techniques to extract image details.

Optical Microscopy utilizes white light and the size range of the particle that could be viewed is limited to half of its wavelength i.e. particle size is limited to 200 nm. For confocal a resolution in 50-100 nm range can be obtained.

Measurements performed:-

Rate of fluorescence, dimensions of living cells, rate of scattering

Applications

• To describe Nano mechanical effect of charged molecules on single DNA molecules [8].

• To determine the flexural rigidity of individual microtubules bound to polystyrene beads [9].

Advantages Disadvantages

Optical tweezers are able to generate higher trapping forces for a given laser power and can be constructed with lower NA microscope objectives[10] Trap stiffness depends on the gradient of the optical field present. Moreover optical perturbations will affect the intensity or the intensity distribution.

Optical tweezers can be used to directly measure forces on trapped objects with a greater accuracy[10] Optical interference can result in the generation of ghost traps.

With the help of optical tweezers we can isolate a single molecule thus simplifying the system under consideration. This eliminates the interactions between other molecules that might complicate the analysis [10]. Optical tweezers also lack selectivity and exclusivity [11] i.e. Optical tweezers exert force on microscopic objects that are transparent to laser light. Since there are numerous such objects inside a cell, optical tweezers cannot selectively operate in the intracellular