Phase (different interference) contrast microscopy, Biology

Assignment Help:

Phase (different interference) Contrast microscopy:

Living cells are mostly   transparent. For viewing under ordinary light microscope, therefore, live cells must be stained with vital stains, or these must be fixed and then stained with acid or basic dyes. Zernicke (1940) designed a phase contrast microscope for viewing unstained living cells. This microscope has the same resolving power as the ordinary light microscope. but takes advantage  of the fact that light rays pass through  various cells parts at different velocities due to varying thickness and densities  of  the parts. In other words, various cell parts have different refractive indices i.e. they refract or bend the light rays to different extents. Obviously, light waves emerging from different cells parts are out of phase with each other. A phase contrast microscope converts these differences in phase to differences in light intensity, producing an image with good contrast, much of what we know about cell division, cell under phase contrast microscopes.

Merton (1947) Ambrose, Dyson, Smith and others have contributed in designing interference microscopes based on principles similar to those of phase contrast microscopes, but with an added advantage of giving quantitative data of the measurement of dry weight of various cell parts.


Related Discussions:- Phase (different interference) contrast microscopy

Explain about ia muscle-spindle, Which of the following occur in response t...

Which of the following occur in response to an increase in the length of the right knee extensors in response to a quick tap applied to the right patellar tendon?  An increase in t

Which term refers to muscles with less than normal tone, In biological stud...

In biological studies which of the below terms is used to refer to muscles with less than normal tone? Is it: a) Latent b) Atonic c) Flaccid d) None of these ANSWE

Ion channel-linked receptors, Ion channel-linked receptors will transmitter...

Ion channel-linked receptors will transmitter-gated ion channels or ionotrophic receptors that   are included in the rapid synaptic signaling among electrically excitable cells. No

Demonstrate the cause of the mutant trait, A protein that is normally a sin...

A protein that is normally a single-pass transmembrane protein is absent from the cell surface of the mutant cell line YTM-15. When labeled so that the protein can be localized, yo

What do you mean by ventricular arrhythmias, Q. What do you mean by Ventric...

Q. What do you mean by Ventricular Arrhythmias? Considerable disagreement exists regarding the significance of resting ventricular ectopic beats. In study comparing the coronar

Explain adverse effects of lactic acidosis, Adverse effects of Lactic acido...

Adverse effects of Lactic acidosis- Lactic acidosis and severe hepatomegaly with steatosis have been reported with use of other nucleoside analogs. The most common adverse effe

Expression of variability, In the preceding section we emphasised the fact ...

In the preceding section we emphasised the fact that cvolution or the continuous adaptations to the environment can take place only when pheiiotypes exhibit variability. In the abs

Domestic effluents - causes of water pollution, Domestic Effluents - Causes...

Domestic Effluents - Causes of Water Pollution Liquid waste produced daily in kitchen, bathroom and toilet are discharged directly or through canal, river or any other water b

Allele-specific ligation, Allele-specific ligation  is the technique permit...

Allele-specific ligation  is the technique permitting discrimination of two allele at locus by giving two short synthetic oligonucleotides which would bind ajjacent to teach other

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd