Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Light microscopy:
Microscopy started with light microscopes using visible light to illuminate the objects, the most used and familiar microscope is called compound light microscope. Its simplest form it consists of two optical lenses, one at each of a hollow tube. The lens closer to the object is called objective and the one closer to the observer eyes is called eyepiece. The object, mounted upon a glass slide, which is put upon a centrally perforated satge under the objective, is illuminated by light , a mirror is fitted below the stage to focus light on to the object, a third lens system ,called condenser may be fitted between the mirror and the stage to concentrate the light. The limit of the resolving power of best compound light microscopes is about 0.2 achieving a magnification of about 2000 times the size of the objects. Thus these microscopes can resolve even most of the bacteria, but they cannot reveal the internal details of bacterial cells.
Use of ground glasses as optical lenses to magnify objects was presumably realized several centuries ago. The first name on record is of Conrad Gesner who used magnifying lenses to observe certain foraminifera's. Next Zacharias Janssen (Dutch 1590) constructed, together with his father, Hans Janssen the first compound light microscope to study insects which could magnify objects 10 to 30 times. Galileo constructed microscope with greater magnifying powers and studied the arrangement of facets in the compound eyes of insects. Marcello Malpighi (1628-1694) microscopically studied animal and plant tissues in thin slices of several organs, earning the title of the father of microscopic anatomy, Robert Hooke (English 1665) designed a compound light microscope either a magnifying power of about 42 times and studied amongst other object thin slice of cork discovering cells. Antony van Leeuwenhoek (Dutch 1676) designed single lens microscopes with magnifications approaching 300 times and become the first to observe sperms, blood cells muscle fibres, lenses of eyes, hydrae yeast cells and microscopic organisms in water like bacteria, protozoan's rotifers tec. Earning the little of the father of microbiology so commonly used these days by students in schools and collages all over the world , was developed from Hooke model by Wilson (1970).
Zigmondy (1900) designed an ultra microscope using ultraviolet rays in place of ordinary light and quartz lenses in place of ordinary glass lenses, achieving a resolving power of0.1 and magnification of about 4000 times.
why manures are better than fertilizers
Locomotion Continuous formation of new pseudopodia keeps amoeba in constant locomotion .This is called amoeboid movement .It occurs in many other protozoans , in amoebo
What is Carbon Cycle explain briefly? Life on earth is mainly carbon-based. Most of the material substances that make up living organisms consist of organic compounds of carbon
S w i n e fever It is also known as hog cholera and results in high fever and prostration. E t iology : Pestivirus belonging to family Togaviridae is responsi
Phytochrome - Floral Induction Phytochrome a pigment that exists in two different inter convertible forms was discovered by Hendricks and Borthwrick et. al. and was chemically
is crossing over of chromosomes is a method?
Explain Positive Staining Technique? Here, a stain has a positively charged chromophore that gets attached to the negatively charged outer surface of the microbial cell and thu
topics relating research on microorganisms and their application ?
Explain Minerals requirement during thyphoid Minerals: Loss of electrolytes and water is observed due to diarrhoea. Thus liberalizing on sodium intake through salty soups,
Doppler echocardiogaphy is based on the Doppler effect, which was described by the Austrian phy$icist Christian Doppler in 1842. The Doppler effect states that sound frequency
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!
whatsapp: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd