Histology Quiz 5

What color does the nucleus stain

purple

What phase is the nucleus seen in during H&E stain

interphase

what color does the nuclear membrane stain

dark blue

how are nuclear pores seen

only with electron microscopy

Heterochromatin is ________________

basophilic

what kind of chromatin does not take up nuclear stains

Euchromatin

what color does the cytoplasm stain

pink

what structure of the cytoplasm is

• the phospholipid bilayer

• Not able to be seen with H&E stains

• Plays an important role in antibody-antigen reactions

Plasmalemma

what structure(s) in the cytoplasm can not be seen with H&E stains

Plasmalemma

Mitochondria

Golgi Apparatus

Centriole

What structure of the cytoplasm is seen as a bluish tinge

Ribosomes

What structure of the cytoplasm is seen as basophilic and bluish

rough endoplasmic reticulum

what structure of the cytoplasm does not stain with H&E but can be seen as a nuclear halo around the nucleus

Golgi apparatus

what structure of the cytoplasm is found within the vacuoles and seen under the microscope with a yellow/brown pigment

Lysosomes

Adsorption

Dye is embedded onto the tissue via chemical bonding

An example of adsorption is

Eosin binding during H&E

particles bind to the surface of tissues through adsorption via

Ionic Bonds

Covalent bonds

Hydrogen bonds

What kind of bond are also called electrostatic bonds, and are formed as a result of tissues being attracted to one another because they have opposite charges

Ionic bonds

what kind of bond is seen typically in organic chemicals between carbon, hydrogen or oxygen and form when atoms share electrons

Covalent bonds

What kind of bond typically occurs between hydrogen+oxygen or hydrogen+nitrogen and occurs when a covalently bonded hydrogen is attracted to atoms with a high electronegative charge

Hydrogen bonds

WHat kind of bond is considered weak?

Hydrogen bonds

What are Van der Waals forces

weak attraction of molecules to electrons of nearby molecules

absorption

dye is absorbed into the tissue physically

what is an example of absorption

Oil Red O when staining lipids

what method of staining is when a chemical reaction takes place between a chemical reagent and the tissue where the product of the reaction is visible color

Histochemical

what is an example of histochemical staining method

PAS staining for carbohydrates

what method of staining is when tissue has affinity for silver salts

Silver impregnation

Dyes are organic compounds derived from…

tar or benzene

chemical groups that allow for the viewing of color are called

chromophores

benzene attached to chromophoric groups are called

a chromogen

chromogens require _______ for color to be seen

an auxochrome

what group is the main basic auxochrome

Amino groups (NH2)

The main acidic auxochrome group is

Sulfonic acid groups (SO3H). Others include COOH and OH

Basic dyes have a __________ charge

positive

basic dyes are also called

cationic dye

basic dyes are usually a …

chloride salt

examples of basic dyes are

crystal violet, safranin

acidic dyes have a __________ charge

negative

acidic dyes are also called

anionic dyes

acidic dyes are usually a

sodium salt

examples of acidic dyes include

Orange G, picric acid

examples of amphoteric dyes

hematein, lithium carminate

what is the isoelectric point

where the pH has a net zero charge

what are amphoteric

when the pH is lower than the isoelectric point it acts as a cationic dye, and when the pH is higher than the isoelectric point it acts as an anionic dye

how does pH of the dye affect binding

establishes the charge of the dye molecules and determines if the dye will bind with the tissue

how does temperature affect the binding of dyes

rate of diffusion of dyes increases as temperature increases

how does concentration of dyes affect binding

the greater the concentration of dye, the greater the rate of binding

how do dissolved salts affect binding of dye

affects the intensity of the stain if salts have dissolved in the staining solution

how does fixative choice affect dye binding

certain fixatives affect the ability for dyes to bind

how does formaldehyde affect dye binding

Reacts with amino groups in tissue and makes it unable to bind with eosin

increases the uptake of positively charged dyes

how does potassium dichromate affect dye binding

reacts with COOH and OH groups and causes tissues to take up less hematoxylin and more eosin

how does zenker affect dye binding

causes diminished nuclear staining

how does bouin affect dye binding

causes diminished nuclear staining

how does unbuffered formalin affect dye binding

causes diminished nuclear staining

how does picric acid affect dye binding

makes tissue very receptive to negatively charged anionic dyes

how does mercuric chloride affect dye binding

increases the uptake of positively charged basic cationic dyes

how does osmium tetroxide affect dye binding

by increasing the uptake of positively charged basic cationic dyes

what is progressive staining

the reaction is stopped once the intensity of the stain reaches the desired level. used with counterstains

what is regressive staining

tissue is overstained and then differentiated

what are mordants

substances that act like a bridge between the dye and the tissue

mordant + dye =

lake

what kind of staining are mordant dyes used with

regressive staining

How are basic dyes differentiated

by weak acid solutions

what is an example of a basic dye being differentiated with a weak acid solution

aluminum hematoxylin is differentiated with dilute HCl

How are acidic dyes differentiated

by weak alkaline solutions

what is an example of an acidic dye being differentiated by weak alkaline solutions

eosin differentiated with dilute ammonium hydroxide

Adding extra mordant to the differentiating solution will cause…

bound dye to dissolve from the tissue

how do oxidizers differentiate tissues

tissues that have the most dye bound will retain color where tissues with less dye remain colorless

how do solvents differentiate tissues

dye will want to move from a solution of high concentration to a solution of low concentration

what are the 2 mechanisms for nuclear staining

basic (cationic) dyes and dyes combined with metal mordants

how are basic (cationic) dyes used for nuclear staining

forms dye-salt unions, dependent on the presence of nucleic acids

how are dyes combined with metal mordants used in nuclear staining

required with tissues where nucleic acids have been altered/removed or tissues without a negative charge

cytoplasmic staining relies on

proteins or charged groups on their amino acid side chains

neutral pH of proteins is

6

when the pH is below 6…

there is a net positive charge which attracts anionic dye

when the pH is above 6…

there is a net negative charge which attracts cationic dye

hematoxylin is a naturally sourced compound from the

hematoxylin tree

hematoxylin is unable to stain until it has

been oxidized into a mineral called hematein

on its own, hematoxylin has a __________ affinity for tissue

low

hematoxylin has a low affinity for tissue until it has been

combined with a metallic mordant

mordant dye complex has a _________ affinity for nuclei

high

the most common mordant dye lakes are

hematin + aluminum

Hematein + iron

what color lake does aluminum make when it is used as a mordant

blue

what color lake does iron make when it is used as a mordant

black

dyes that require mordants are called…

indirect dye

the most critical step in regressive staining is

differentiation

the most frequently used differentiator is

acid alcohol

the oxidizer for Harris Hematoxylin is

mercuric chloride

sodium iodate

the mordant for Harris hematoxylin is

potassium aluminum

the solvent for Harris hematoxylin is

Ethanol

Harris hematoxylin is used for what staining methods

progressive and regressive

what can be added to Harris hematoxylin to make staining more specific

Acetic acid

What is the oxidizer for Delafield hematoxylin

natural by light or air

what is the mordant for Delafield hematoxylin

ammonium aluminum

what is the solvent for delafield hematoxylin

ethanol

what does delafield hematoxylin smell like

wine

what staining method is delafield hematoxylin used with

regressive

what can be added to delafield hematoxylin to stabilize it

glycerol

what is the oxidizer for mayer hematoxylin

sodium iodate

what is the mordant for mayer hemaotxylin

ammonium aluminum

what is the solvent for mayer hemotoxylin

distilled water