practical 5- staining techniques

Question 1

what is a dye

Answer 1

a salt of an aromatic compound which dissolves in water or aqueous solution to produce coloured ions

Question 2

what are dyes classified by

Answer 2

their chromophores

Question 3

what is a chromophore

Answer 3

a colour bearing chemical configuration

Question 4

what are the 3 types of chromophores

Answer 4

quinonoid

azo

nitro

Question 5

what is an auxochrome

Answer 5

a radical which infers a charge to the dye (acidic or basic properties to the dye)

Question 6

why must a dye contain an auxochrome

Answer 6

to speed up the process and prevent the dye from elute when washing

Question 7

what is a chromogen made up of (true dye)

Answer 7

chromophore and auxochrome

Question 8

what are the 5 main staining processes used in histology

Answer 8

vital staining
elective staining
histochemical staining
metallic impregnation
staining with dyes (general physical and chemical reactions, metachromasia)

Question 9

what does a H&E stain identify

Answer 9

cell morphology
atrophy
hypertrophy
ectopic calcification 
inflammation
infarction

Question 10

which stain identifies acidic mucins

what can this stain also be used in combination with

Answer 10

alcian blue 8GX

PAS

Question 11

what does the PAS (periodic acid schiff) stain identify

Answer 11

neutral mucins

anything containing 1:2 glycol groups

collagen, fungi, basement membrane

Question 12

what must an amyloid stain be used in conjunction with

Answer 12

polarising microscopy

Question 13

which stain is most suitable in lipids

Answer 13

lipochromes (elective solubility- oil red O or sudan red dyes)

Question 14

what does perls (prussian blue) stain identify, what does it also demonstrate

Answer 14

asbestos bodies

demonstrates ferric iron using potassium ferrocyanide in a dilute HCl solution

Question 15

what are the following stains categorised by

verhoeff, weigert, orcein, millers

Answer 15

elastin stains

Question 16

which stains uses the silver impregnation technique and is an example of an argyrophillic reaction

Answer 16

reticulin

Question 17

what does masson fontana identify

Answer 17

melanin

Question 18

what is meant by an argentaffin reaction

Answer 18

ability to reduce a solution of silver nitrate to metallic silver without the use of an extraneous reducing agent

Question 19

what is the difference between mason trichome and mallory trichome stain

Answer 19

distinguish collagen from muscle

Question 20

what does MSB (martius scarlet blue) stain

Answer 20

fibrin

Question 21

what does the gram stain distinguish between

Answer 21

gram +ve and gram -ve organisms

Question 22

what does grocott stain

Answer 22

fungi

Question 23

what does ziehl neelson stain

Answer 23

mycobacterium

Question 24

what does modified giemsa stain

Answer 24

helicobacter pylori

Question 25

what does von kossa stain

Answer 25

calcium, ecotopic calcium deposition

Question 26

how does a metachromatic stain work

Answer 26

1 dye bath produces 2 colours

certain cell constituents can absorb light at 1 wavelength and re-emit light at different wavelength