INTRODUCTION TO MICROSCOPY CELL BIOLOGY
MICROSCOPY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Photocathode
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Charge Coupled Device (CCD)
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PMT (Photomultiplier Tube)
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Photodiode
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Detailed explanation-1: -Probably the best-known sensor for confocal imaging so far, is the classical PMT (Fig 01), which started its career more than 80 years ago in the early 1930’s[1]. It is based on the photoelectric effect, first described by H. Hertz[2] and interpreted by A. Einstein[3].
Detailed explanation-2: -The PMT is used in concert with electronic amplification (gain) to further brighten signal from fluorescently labeled specimens. The difference between a confocal and a standard microscope is the use of an aperture or pinhole (also called an iris).
Detailed explanation-3: -Since the pinhole reduces the amount of signal, a photomultiplier tube detector (PMT) is used. A PMT is an extremely sensitive detector that can multiply the current produced by light by up to 100 times. PMTs contain a photocathode, which when struck by an incoming photon of light, emits an electron.