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LIGHT MICROSCOPY method.. Allows to see only cell NUCLEUS and only CYTOPLASM, because magnification of light microscope is not sufficient for revealing of ORGANELLS and
CHROMOSOMES. If objective lenses have magnification x40 and ocular lenses - x7,
TOTAL magnification of LIGHT microscope is:
40 x 7= 280 times.
Steps for slide manufacturing in method of
light microscopy:
a)
Fixation of specimen in FORMALIN solution.
b)
Dehydration – is removal of water from specimen. Put it in ETHYL ALCOHOL.
c)
Embedding – is infiltration of specimen by melted. PARAFFIN.
d)
Sectioning – is cutting of specimen by histologic knife with aim to get SECTIONs with thickness 7 micrometers. Device for this – is MICROTOME.
e)
Staining of section by histologic DIES.
Dies are classified on 2 types: 1) COMMON dies., 2) SPECIAL dies
Common dies reveal only pink cytoplasm and blue nucleus,
without chemical identification of cellular content.
Common dies are classified on: a) BASIC dies. It is HEMATOXYLIN. It stains NUCLEUS in BLUE colour. b) ACIDIC dies. It is EOSIN. It stains CYTOPLASM in PINK colour.
Special dies reveal only ONE
CHEMICAL of cellular content.
It may be: ORSEIN for revealing of ELASTIC fibres; SUDAN BLACK for staining of LIPID droplets into BLACK colour.
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ELECTRON MICROSCOPY method (=EM). Allows to see: ORGANELLS, C HROMOSOMES, CHROMATIN, because electron microscope gives magnification x5.000 times up to x30.000 times. There are 2 types of EM method:
A)
TRANSMISSION EM (
TEM method). It gives PLANE picture of organelles and chromatin;
B)
SCANNING EM (
SEM method). It gives
3-D image of cell.
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HISTORADIOAUTOGRAPHY method. It allows to evaluate RATE of DNA duplication. If in microslide number of SILVER GRAINS on phone of nucleus is big, it signifies about AST rate of DNA duplication.
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IMMUNOCYTOCHEMISTRY method. It allows to see proteins-RECEPTORS on the surface of PLASMA MEMBRANE. If after injection of LABELED MONOCLONAL ANTIBODIES into rat, plasma membrane is stained into pink colour (into colour of LABEL), it means :proteins-RECEPTORS present.
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PHASE CONTRAST MICROSCOPY method. It allows to see ALIVE and NON-stained cells, to evaluate RATE of SPERMATOZOA movement.
Составитель – доцент В.В. Бондаренко.
