Instrumentation

Description:	Instruments Chapter 3
Category:	Histology
Created by:	nperez on 2009-05-21

Question	Answer
compound microscope	Light microscope
The lens system consist of objectives and oculars	light microscope
provide image maginification and image resolution	Objective lens
Scanning lens, intermediate lens, high powered dry lens and immersion lens	types of objective lens
will give an image surrounded by color fringes	Uncorrected lens also know as chromatic aberration
are corrected for two colors red and blue and are found on most lab microscopes	achromatic objectives
are corrected for three colors and for other lens aberrations	Apochromatic objectives
are more expensive and not necessary for routine use. used for photomicrography	Apochromatic objectives
a defect in lens system	aberration
eyepiece	oculars
have a x10 mag and x5 oculars are frequently used on student microscope x15 oculars preferred by microscopist	oculars
is determined by multiplying the mag of ocular w/the objective	total mag obtained w/a microspe
substage found below can be moved up/down	substage
on modern microscopes consists of a condenser and iris diaphragm	substage
function primarily to concentrate light on the tissue section	condenser
should be centered accurately	condenser
regulated by iris diaphragm and should be varied w/t different objectives	amount of illumination
should be adjusted so that peripheral light rays are blocked and light passing through the tissue should be limited so that it fills the front lens of the objective	iris diaphragm
keep covered when not in use, clean lens w/lens paper, remove immersion oil immediately after use	microscope maintenance
use xylene on the ofectives as a last resort, dont dismantle objectives,	microscope maintenance
when using immersion oil becareful, make sure that the high powered dry lens inst dragged through the oil	microscope maintenance
reduce light t/a minimum or turn it off when not in use. remove slides from stage when not in use	microscope maintenance
always focus upwards, never downwards, especially w/t higher power objectives	microscope maintenance
do not touch lens surfaces w/fingers	microscope maintenance
used in identification of crystals. Talc, silica or urates	polarizing microscope
used in identification of amyloid stained w/congo red	polarizing microscope
used to examine tissue for substances exhibiting the phenomena of double refraction, anisotropism and birefringence	polarizing microscope
transmitting light unequally in different directions	birefringence
having unlike properties in different directions	anisotropism
is achieved by interposing a polarizing device between the light source and specimen and inserting a second polarizing filter between the specimen and the eye	polarized light
vibrates in many planes	natural light
vibrates only in one plane	light emerging from the polarizer
can be converted to a polarizing microscope by placing one piece of polaring film on top of light source and another on top of the microscope slide.	light microscope
through this microscope amyloid stained w/congo red, will show apple green birefringence	polarizing microscope
used for examination of unstained specimens	phase-contrast microscope
used to examine unstained living cells and allows transparent objects to be seen	phase-contrast microscope
can be converted to a phase-contrast microscope by replacing the condenser and objective w/special phase equipment	a standard binocular microscope
not used in routine histology	phase-contrast microscope
directly transmitted light is excluded	dark field microscope
only scattered or oblique light is utilize	dark field microscope
objects appear much larger than they are, bcuz of their light scattering properties and frequently fine structures	dark field microscope
used for the study of unstained microorganisms and is rarely used in routine histopathology	dark field microscope
phenomeonon in whic light of one wavelenght is absorbed by as substance and instantly remitted as light of a longer wavelength	fluorescence microscope
substance is bombarded w/short-wavelenght light in the ultraviolet, violet or blue range and visible light is emitted	fluorescence microscope
two types transmission and scanning	electron microscope
the specimen either transmits electrons producing electron lucent or clear areas in the image	transmission electron microscope
the specimen deflects electrons (producing electron-dense, or dark area in the image	transmission electron microscope
a two-dimensional black and white is seen on fluorescent screen	transmission electron microscope
cells and ultrastructure of the cells can be appreciated w/	transmission electron microscope
useful in dx of kidney disease and in tumor identification	transmission electron microsocpe
has replaced the electron microscope, in tumor diagnosis	immunoperoxidase
a dramatic three-dimensional image	scanning electron microscope
the electron beam sweeps the surface of the specime and releases secondary electrons	scanning electron microscope
has a great depth of focus	scanning electron microscope
very expensive, requires skilled operator	scanning electron microscope
found in large instistutions	scanning electron microscope
Rotary, sliding and freezing microtomes	most commonly used microtomes in histology
used for sectioning glycol methacrylaten and paraffin embedded material	rotary microtome
operates w/a screw feed	rotary microtome
block moves up/dowm and either the knife or block advances a preset number of micrometers w/each revolution of the wheel	rotary microtome
used for sectioning celloidin and large paraffin blocks	sliding microtome
block held stationary and the knife is moved along a horizontal plane past the block face	sliding microtome
not used in routine histology	sliding microtome
has been replaced by the cryostat	clinical freezing microtome
free-floating sections for some special stains are easier to obtain with this than with the cryostat	clinical freezing microtome
a sharp knife must have and edge free of defects, is essential to obtain a good section	microtome knifes
successful sectioning of poorly processed tissue is possible w/a	good knife
nondiagnostic sections m/b obtained w/a	poor knife
used for cutting plastics	glass knifes
used to section glycol methacrylate embedded materials	ralph knifes
used for sectioning, paraffin, celloidin, carbowax and frozen tissue	microtome knives
made from high-grade tempered steel and are wedge-shaped, biconcave or planoconcave	microtome knives
used for paraffin, carbowax, and frozen sections	wedge-shaped knife
preferred for celloidin	planoconcave knife
requires both block and knife to be kept wet	the wet celloidin method
planoconcave knife can be used for this method	the wet celloidin method
used for early hand sectioning	bioconcave knife
has been replaced by the plane wedge knife	bioconcave knife
rarely used	bioconcave knife
wedge angle 15 to 18	microtome knife
27 to 32	bevel angle
condition of knife is critical, c/b determined w microscopic examination w/x100 mag	mictrome knife
are stainless steel razor blades that are held secure in a holder on the microtome	disposable blades
used to cut ultrathin sections for EM	diamond knifes
should be discarded in punture-proof containers	disposables blades and glass knifes
if used in cryostat, they need to be autoclaved before disposal	disposable blades
knife tilt	clearance angle
when cutting sections, angle should be 3 to 8	clearance angle (knife tilt)
should be determined with each knife	clearance angle (knife tilt)
c/b corrected by adjusting the knife so that the correct clearance angle between knife and specimen is obtained	irregular, skipped or thick and thin sections
horizontal edges of block are not parallel	ribbons are crooked
mictoromy artifact	holes in sections
should be performed less aggresively	block facing
when holes appear in ribbons, an there is sufficient tissue in block,	ribbons should be cut until holes disappear
dull knife	ribbon will not form
depends on enough heat being generated by friction occurring as each section is cut to cause the sections to adhere to each other	ribbon formation
caused by dull knife or too little knife tilt	section lifts from the knife as the block is raised
warm room or paraffin to soft	section lifts from the knife as the block is raised
occurs in very hard tissue like uterus	washboarding or undulations
occurs when a block or knife has not been tightly clamped	washboarding or undulations
too much knife tilt or worn microtome parts	washboarding or undulations
overdehydration or lack of moisture	chatter, microscopic vibration appear in sections
treating faced block for a few sections with wet cotton, or dip thumb in flotation bath and rugh the block	to remove chatter, or microscopic vibration
dull knife, too much tilt, or cutting to rapidly	microscopic chatter
too little knife tilt	sections are skipped or vary in thickness
dull knife or gummed w/paraffin	sections are compressed, wrinkled or jammed
too little knife tilt, too rapid cutting or too warm room	sections are compressed, wrinkled or jammed
keep free of paraffin by wipping up w/a gause damped w/xylene (nerver wipe down	knife edge
defect in knife	lenghtwise scratches or splits in ribbons
static electricity, add moisture to air by breating on block and knife or boil water in open pan near microtome.	section flies or sticks to nearby objects
refrigerated chamber containing a microtome (rotary)	cryostat
cooled by mechanical regrigeration	cryostat
sections are picked up directly onto slide	cryostat
knife m/b sharp and edge free of defects	cryostat
wedge-shaped knife is commonly used.	cryostat
antiroll devices are designed for this knife	wedge-shaped knife
operated at -20c	cryostats
slow freezing allows water present in the tissue to form	ice crystals
are seen as artifacts	ice crystal formation
open and closed	two types of processors
tissue is transported from one solution to the next	open processors
tissue is stationary and fluids are pumped in and out of the chamber	closed processors
are computerized w/a digital readout to indicate the exact instrument status	closed processors
major advantage is that specimen cannot dry out w/i the chamber	closed processors
disadvantage is that not all reagents c/b used on these processors	closed processors
mercury, dichromate containing fixatives and chloroform, cant b/used on this processor	closed processors
heat and vacumm	closed processors
speed up processing	heat and vacumm
use carefully on bx specimens	heat and vacumm
m/b kept clean and a routine reagent rotation	processors
fluid levels m/b higher than tissue	processors
temp of paraffin m/b carefully adjusted to no more than 2C to 4C above melting point	processors
temp m/b monitored and recorded daily	processors
used to float out ribbons	flotation baths
maintained at 5C to 10C below the melting point of paraffin used for embedding	flotation baths
ribbons should be stretched gently, small wrinkles and folds should be teased out	flotation baths
a mixture of egg white and glycerin w/elmers glue	albumin
gellatin, agar and elmers glue	water bath additives
poly-L lysine-coated slides	used for frozen sections, some to be stained in microwave and paraffin sections to be stained w/immunoenzyme technique
postive charged attracts frozen and paraffin tissue sections elctrostatically	positive charged slides
no adhesive needed	positive charged slides
background staining is eliminated and section loss w/staining procedures is reduced	positive charged slides
fairly expensive and not recommended for routine work	positive charged slides
dissolve 1g of gelatin in 1L of distilled water w/heat. cool and add.1g of cromium potassium sulfate, store in fridge.	subbed slides
after section is mounted on slide	it should be dried in the oven, hot air dryer or warming plate
slides are dried to	remove water
white spots that can be seen in tissue when slides are removed from xylene	incomplete deparaffination
maintain a temp just above the melting point of paraffin	dryers and ovens
can be used for overnight drying of immunoperoxidase slides but temp must be kept below 60C	ovens
are maintained at 37C	incubators
used for enzyme reactions and for some special stains	incubators
used for storing may of the reagents used in histology, enzyme histochem reagents, ihc reagents, and buffer solutions	freezers and refrigeratos
maintained at about 4C and should not be allowed to reach a temp above 10C	The refrigerator
-20C	Freezer temp
for IHC surface markers of lymphoid tissue or estrogen/progesterone receptor the freezer should be at what temp	-70C
are used for performing special stains, for fixation, processing, drying of sides and other procedures	microwave ovens
is dependent on exposure of time, solution volume and oven wattage	heat generated by microwave
linear,revolving and robotic	automatic stainers found in histo
transfer slides from one container to the next w/t same time allowed in each container	linear stainer
also dries slides	linear stainer
operate on the same prinicple as open tissue processor	revolving stainer
are the most flexible stainer	robotic stainers
allow computerized programming w/ability to return slides to same container used in a previous step	robotic stainers
vary in slide capacity but slides may be continously loaded	linear stainer
are batch stainers, one batch of slides m/b finisher before the next one is started	robotic and revolving stainers
used to measure acidity.	pH meters
scale goes from 0 to 14	pH scale
defined as netgative power to which the number 10 m/b raised to express the moles per liter concentration of solutions hydrogen ions	PH
has melted paraffin w/warm storage for embedding molds, small warming and chilling plates, and larger chiller plate for rapid chilling of embedded tissue blocks	embedding center
paraffin is kept 2C to 4C above melting point of parffing used	embedding center