HISTO 210 Test 1 | Complete Solutions (Answered)

HISTO 210 Test 1 | Complete Solutions (Answered) Why do we stain tissues? Most tissue are transparent and we would not be able to distinguish between internal structures as well as between tissue types A _______ is a coloured substance capable of attaching to a tissue component and colouring it, while a __________ is the alcoholic or aqeous solution of a dye a) Stain; dye b) Dye; stain c) Chromophore; dye d) Dye; chromophore T/F All stains are coloured to be able to colour the tissue False - sometimes a stain is colourless, and when it reacts with a tissue component it produces a colour Which of the below is false regarding dye classification? a) Natural dyes are obtained directly from nature b) Artificial dyes are man-made and derived from hydrocarbon benzenes c) The majority of dyes we use are natural dyes d) The majority of dyes we use are artificial dyes Which of the below is false regarding hematoxylin? a) Used in most labs as a routine stain b) Purple or blue crystalline compound that is mixed into solution c) From logwood tree bark d) Is typically a nuclear stain, but can demonstrate other tissues e) All of the above are true **Yellow or red crystalline structure! Which of the below is derived from lichen and is a red brick pigment? a) Saffron b) Carmine c) Hematoxylin d) Orcein Which of the below is derived froma cochineal beetle and is a red? a) Saffron b) Carmine c) Hematoxylin d) Orcein Which of the below is derived from a dried stigma of the Crocus savitus or Gardinia Florida and is yellow/orange? a) Saffron b) Carmine c) Hematoxylin d) Orcein Which of the below is false regarding benzene? a) It is a coloured artificial dye that helps to stain tissues b) It is a flammable liquid with a relatively high melting point, and is considered carcinogenic c) Its double bonded structure allows for resonance, which can be manipulated with chromophores to produce colour d) The delocalization theory is what describes the resonance experienced in benezene Explain how benzene is a colourless substance that is able to produce colour in artificial dyes? Benzene contains 3 pairs of double bonds that are constantly moving, normally its absorbance is within the UV range, however when a chemical change, such as a chromophore is introduced, these double bonds vibrate at wavelenghts between 400nm and 750nm (visible light) so colours are visible Which of the below represents the coloured component of the dye? a) Chromophore b) Chromogen c) Auxochrome d) None of the above Which of the below is required for a dye to attach to a tissue? a) Chromophore b) Chromogen c) Auxochrome d) None of the above Which of the below is a molecular structure that causes visible wavelengths to be absorbed? a) Chromophore b) Chromogen c) Auxochrome d) None of the above Which of the below make a dye go colour fast? a) Chromophore b) Chromogen c) Auxochrome A dye is a) Chromophore + auxochrome b) Chromogen + auxochrome c) Chromophore + chromogen d) none of the above Which of the below contains N=N chromophore joining benzene or napthalene rings? a) Azo-coupling b) Quinoid rings c) Nitrogrouping d) None of the above Which of the below chromophores can be found in ortho or para forms? a) Azo-coupling b) Quinoid rings c) Nitrogrouping d) None of the above Picric acid has which of the below chromophores? a) Quinoid rings b) Azo-coupling c) Nitro-grouping Eosin stain and safranin both contain which of the following chromophore groups? a) Quinoid rings b) Azo-coupling c) Nitro-grouping T/F Auxochromes exert their fasting effect when in solution and become ionized True Which of the below auxochromes become cationically charged in solution? a) Carboxyl group b) Sulphate group c) Hydroxyl group d) Amino group A cationic auxochrome makes a _______ dye which stains ____________ tissue a) Acidic; negative b) Basic; negative c) Acidic; positive d) Basic; positive An anionic auxochrome makes a ______ dye and stains ______ tissue. a) Acidic; negative b) Basic; negative c) Acidic; positive d) Basic; positive In picric acid, the OH is the a) Auxochrome b) Chromogen c) Chromophore d) Dye In picric acid, the NO2 groups are the a) Auxochrome b) Chromogen c) Chromophore d) Dye In picric acid, the NO2 groups with the benzene ring are the a) Auxochrome b) Chromogen c) Chromophore d) Dye Which part of the dye acts as a salt when dissolved in water? a) Auxochrome b) Chromogen c) Chromophore _______ dyes will stain collagen, RBCs, and cytoplasm while _________ dyes will stain DNA, chromatin, RNA, lipids, and certain mucus. **include whether it is cationic or anionic Acidic (anionic); basic (cationic) Which of the below is affected by the pH of the dye solution? a) Anionic dyes b) Cationic dyes c) Amphoteric dyes d) Neutral dyes Describe the coloured part, colourless part, and auxochrome charge for an Anionic dye. Give example of the colourless ion and stain. Anionic = acid - chromogen = negatively charged - Colourless part = positive = K+ or Na+ - Auxochrome = NEGATIVE charge Eosin Describe the coloured part, colourless part, and auxochrome charge for a Cationic dye. Give example of the colourless ion and stain. Cationic = basic - chromagen = Positively charged - colourless part = negatively charged Cl-, sulphate, acetate - Auxochrome = positively charged Hematoxylin Which of the below is true regarding an anionic stain? a) The chromogen is Negatively charged b) The auxochrome is negatively charged c) The non-coloured portion is negatively charged d) The basic component is coloured in an anionic dye, the _________ component is coloured whie the ________ component is colourless acidic; basic in a cationic dye, the _________ component is coloured whie the ________ component is colourless basic; acidic Which of the below is false regarding neutral dyes a) Both parts of the dye molecule contain a chromophore b) They are soluble in water c) They have an overall neutral charge due to a combination of cationic and anionic dyes d) All of the above are true *not soluble in water, typically dissolved in methanol Romanowsky stain is an example of a a) Cationic dye b) Anionic dye c) Amphoteric dye d) Neutral dye An amphoteric dye in solution with a pH above its isoelectric point will behave as a (n) ____________ dye and stain ___________ charged tissues. Anionic dye; positively charged An amphoteric dye in solution with a pH below its isoelectric point will behave as a(n) __________ dye and stain _________ charged tissue. Cationic; negatively charged T/F Fixatives can bind with chemical groups in tissues and make them unavailable for staining True Which of the below is false regarding factors that affect dye binding a) pH of a solution establishes the charge on the tissue element and dye molecule b) Increasing temperature will increase the rate of staining c) Salts can increase or decrease staining intensity d) Concentration will typically increase the dye binding e) All of the above are true Basophillic/acidophillic describe ________ while cationin/anionic describe_________. tissues; dyes Which of the below describes a counterstain? a) Used to emphasize and contrast the primary stain b) Used to emphasize and contrast the secondary stain c) Chromophores that change UV to visible light and emit fluorescence d) An extra side group that can change the shade of a dye when added Which of the below changes UV to visible light and emits fluorescence? a) Chromophore b) Chromogen c) Fluorochrome d) Fluorogen A basophillic tissue likes ________ charged dyes, an acidophillic tissue likes ________ charged dyes/ positive (cationic, basic) negative (anionic, acidic) T/F a Modifier group is an extra side gropu that can change the shade of a dye when added True How many numbers are in the colour index number? a) 3 b) 4 c) 5 d) 6 The first 2 numbers of the colour index number represent a) The auxochrome b) The chromogen c) The chromophore d) The specific stain Which of the below does the Biological stain commission certificate number NOT guarantee? a) purity b) max absorbance c) Sample held d) Methods e) Concentration At a pH above the isoelectric point of an amphoteric dye _____________ charged tissues are stained which means they are ____________ (basophillic/acidophillic) pH above isoelectric point = dye is negative, anionic, acidic binds positively charged tissues, which are acidophillic At a pH below the isoelectric point of an amphoteric dye _____________ charged tissues are stained which means they are ____________. (basophillic/acidophillic) pH below = positively charged dye = cationic = basic dye negatively charged tissues; basophillic Which of the below is false regarding the storage of dyes? a) date the produce when received and opened b) Use tap water when making solutions c) Filter before use d) Store in a cool, dark place in dark bottles generally e) All of the above are true Which of the below is not compatible with water? a) Proteins b) Nucleic acids c) Carbohydrates d) Simple lipid Which of the below has a neutral charge always? a) Proteins b) Carbohydrates c) Simple lipids d) Nucleic acids e) Two of the above (b and c) Which of the below is false regarding density as a physical theory of staining? a) Denser tissue = more staining b) Denser tissue = faster staining c) Based on the affinity and charge of tissue and stain b) Liver would stain more than lungs NOT based on this What two factors affect the permeability of a stain? 1. Porosity of tissue; the more porous the easier it is for the stain to diffuse in 2. Size of dye molecule; the smaller the molecule, the easier it is for a stain to penetrate the tissue Which of the below is false regarding permeability of a stain? a) Porosity of tissue affects permeability b) Charge of the dye affects permeability of the tissue c) Size of dye molecule affects permeability of a tissue d) All of the above are true If a large dye molecule has made it into a dense tissue, is it easy or hard to remove by differentiation? HARD T/F permeability plays a large influence on the ability of differentiation to occur True Dyes attached by which of the below physical theories would be easy to differentiate? a) Adsorption b) Permeability c) Selective solubility d) Density Which of the below is used for lipid demonstrations? a) Adsorption b) Permeability c) Selective solubility d) Density A lysochrome is any coloured substance that is soluble in tissue lipids Which of the below is typically used to demonstrate tissue lipids in frozen sections? a) Chromophores b) Lysochrome c) Fluorochrome d) Two of the above can be used Which of the below is the correct order from strongest to weakest chemical bonding? a) Hydrogen bond, ionic bond, van der waals forces b) Hydrogen bond, van der waals forces, ionic bond c) Ionic bond, hydrogen bond, van der waals forces d) Van der waals forces, hydrogen bond, ionic bond Which of the below describes ionic bonding a) A bond in which a charged molecule binds to another molecule due to an opposing, attractive charge b) A bond between two negatively charged non-metals are linked by a proton c) An attraction between neighboring electrons due to partial charges d) A bond between two positively charged ions linked by a proton Which of the below describes hydrogen bonding a) A bond in which a charged molecule binds to another molecule due to an opposing, attractive charge b) A bond between two negatively charged non-metals are linked by a proton c) An attraction between neighboring electrons due to partial charges d) A bond between two positively charged ions linked by a proton Which of the below describes Van der Waals forces a) A bond in which a charged molecule binds to another molecule due to an opposing, attractive charge b) A bond between two negatively charged non-metals are linked by a proton c) An attraction between neighboring electrons due to partial charges d) A bond between two positively charged ions linked by a proton Which of the below is false regarding mordants. a) Used with dyes that have little affinity for tissues to allow for the dye to bind to the tissue b) Usually salts of heavy metals that create a chemical union c) Must have a strong affinity for the dye AND tissue d) Can be applied before or after the dye e) All of the above are true **ONLY before or with What is the correct order of how a mordant is able to increase affinity for tissue? What is this structure called? Dye lake Dye + mordant + tissue Which of the below is false about accentuators? a) create a chemical union with the tissue to increase intensity and selectivity b) Increases the staining capacity of the dye c) Includes phenols, pH controls, or salts d) All of the above are true **NO chemical union If you were to add an acid to a basic dye, what would happen to the intensity a) Increase b) Decrease c) Stay the same d) No effect If you were to add an acid to a acidic dye, what would happen to the intensity a) Increase b) Decrease c) Stay the same d) No effect Which of the below is not a accenturator? a) Phenols b) Heavy metal salts c) pH control d) Salts How do phenols accentuate stains? They disrupt the surface tension which allows the dye to get closer to the tissue and spread evenly Carbol fuschin is an example of which of the below? a) Mordant b) Phenol c) pH control d) Salt Glacial acetic acid is an example of which of the below? a) Mordant b) Phenol c) pH control d) Salt Which of the below does salt allow negatively charged tissues and negatively charged dyes to participate in? a) Ionic bonding b) Van der Waals forces c) H-bonding d) Two of the above e) All of the above Explain how a salt can help a negatively charged dye stain a negatively charged tissue. The +ve portion of the salt will bind to the -ve tissue, lessening the negative charge and allowing the -ve charged dye to get close enough for VdW forces or H bonding to bind A _________ stain requires a mordant or accentuator, while a __________ stain does not indirect; direct __________ is an example of a _________ stain because it needs a mordant, while ___________ is an example of a _________ stain. Hematoxylin; indirect; eosin direct What is the difference between a trapping agent and a mordant? Mordants are stronger bonds between the dye and the tissue, as well are applied BEFORE the stain, while trapping agents have a weaker bond between the dye and the agent, and they are applied after the dye Mordants are applied ________ the dye, trapping agents are applied ______ after the dye. BEFORE, AFTER Is progressive or regressive staining more time sensitive? Progressive T/F Both progressive and regressive stains contain differentiation steps False - only regressive stains do Are regressive or progressive staining methods more precise and intense? Regressive because they are more specific and allow us to tweak the intensity how we desire Explain how an acid or base can be used to cause differentiation. By adding an acid to a tissue stained with a basic dye (such as hematoxylin), you cause the pH of the solution to lower past that of the IP of the tissue. This changes the -ve tissue to ve+ which will reject the ve+ basic dye Acidic differentiation removes _____ dyes from tissue structures, while basic differentiation removes ______ dyes from tissue structures basic; acidic T/F Acid and base differentiation is dependent on the isoelectric point of amphoteric proteins that the dye is bound to True! Which of the below differentiating agents would be the hardest to control? a) Acid or base differentiators b) Alcohol or water c) Oxidizing agents d) Mordants Oxidizing agents target the _________ stained tissues first a) Most b) Least c) Doesn't matter How does a mordant differentiate? a) A weak solution of the same mordant used previously is used which outcompetes with the mordant attached to the tissue for the dye molecules b) A strong solution of the same mordant used previously is used which outcompetes with the mordant attached to the tissue for the dye molecules c) A strong solution of a different mordant used previously is used which outcompetes with the mordant attached to the tissue for the dye molecules d) A weak solution of a different mordant used previously is used which outcompetes with the mordant attached to the tissue for the dye molecules How can a dye be used to differentiate? Dyes of different affinities will compete with each other for tissues, the stronger one will win Which of the below is false regarding how dyes can act as differentiators? a) A dye with a stronger affinity for the tissue will kick off a dye with a weaker affinity b) Size of the dyes can play a factor c) A dye with a fainter intensity will be overcome by a dye with a stronger intensity d) All of the above are true T/F Decolorizing is the complete removal of all macroscopic colour TRUE Oxidation can restore the colour in which of the below a) Acidic dyes b) Basic dyes c) Neutral dyes d) Amphoteric dyes e) Leuco dyes T/F Reduction can restore the colour in leuco dyes once theyve been oxidized False - oxidation can restore the colour once they’ve been reduced Which of the below describes the tissue that will stain a different colour than the original dye during metachromasia? a) Chromgen b) Chromophore c) Chromotropes d) Auxochrome Orthochromatic refers to a) A stain that is not metachromatic b) A stain that is not regressive c) A stain that does not contain an accentruator d) A stain that is progressive Which of the below can a metachromatic dye be a) Anionic b) Cationic c) Neutral d) Two of the above Which of the below does polymerization of dye molecule rely on in metachromatic dyes a) Acid component b) Basic component c) Chromatropes d) Water Which of the below is an example of a chromotrope? a) Squamous epithelial cells b) Bone c) Laminia propria d) Hyaline cartilage The hyaline cartilage in the trachea stains purpleish upon the use of toluidine blue dye due to a) Differentiation b) Orthochromasia c) Metachromasia d) None of the above Hyaline cartilage is a __________ while laminia propria is considered ____________ a) Chromotrope; orthochromic b) Chormotrope; metachromatic c) Chromogen; orthochromic d) Chromogenl metachromatic Which of the below dyes would you not perform DCM (dehydrate clear mount) on? a) Toulidine blue b) H&E c) HPS d) you could do it on all **metachromatic dye which is labile to dehydration wet or aqeous mounting media must be used when staining with a) Progressive stains b) Metachromatic stains c) Regressive stains d) Orthochromatic stains T/F Chromotropes are anionic molecules that bind to cationic metachromatic stains True Which of the below is false regarding metachromatic stains a) Require water to work, and are labile to dehydration b) Are all anionic c) Tissue components will stain a different shade/colour upon polymerization if the dye reacts with it d) Chromotropes are the tissue portions that will be stained metachromatically In a _______ vital stain the dye is introduced directly into the body, while a ________ vital stain is one in which the cells are removed and stained outside the body Intra; supra Which of the below is false regarding histochemical staining? a) The dye causes the colour b) Stable substances as well as unstable substances (Enzymes) can be stained this way c) A chemical reaction between the substance found in tissue and the dye, which produces colour d) Very high specificity T/F A reaction between a tissue component and the dye produces the colour in histochemical reactions True - not the dye itself What are good characteristics of a mounting media? - Little to no colour - No tissue distortion - Fill small spaces in cells - Solidify to hold cover - Not interfere with stain colour/rxn - Not support bacterial/fungal growth Which of the below is false regarding mounting medias a) Resinous mounting media is hydrophobic while aqueous mounting media is hydrophillic b) Aqueous media can be used with slides that have been dehydrated and cleared c) A substance must be added to aqueous mounting media to raise the refractive index d) Resinous mounting media is the most common e) Metachromatic staining and fat stains require aqueous mounting media Which of the below is not required in an aqueous mounting media? a) Bacteriostatic agent b) Substance to increase RI c) Nail polish to seal coverslip d) A solvent e) All of the above are required Are positive or negative controls run every time for most routine histo stains? Positive T/F Nail polish is an example of a ringing media True What are the two most common routine stains? H&E HPS