Biological Staining Lecture Notes PDF

BIOLOGICAL STAINING Terms and principles UNIT LEARNING OUTCOMES  2.1 Discuss routine staining procedures used in histotechnology and cytology  2.2 Perform complete routine histotechnology and cytology staining procedures, including final mounting of slides  2.3 Prepare stains, stock soluti...

BIOLOGICAL STAINING Terms and principles UNIT LEARNING OUTCOMES  2.1 Discuss routine staining procedures used in histotechnology and cytology  2.2 Perform complete routine histotechnology and cytology staining procedures, including final mounting of slides  2.3 Prepare stains, stock solutions and working solutions  2.4 Manage chemicals dyes, reagents, and solutions as required  2.5 Use reagent preparation equipment appropriately  2.6 Washing glassware appropriately  2.7 Describe the structure of dyes 1  2.8 Define dyes, chromophores, chromagens and auxochromes  2.9 Describe the colour index system  2.10 Describe the function of the Biological Staining Commission  2.11 Describe dye classification systems  2.12 Identify examples of natural dyes  2.13 Identify examples of synthetic dyes  2.14 Staining theories and techniques  2.15 Explain direct and indirect staining  2.16 Explain the function of mordants, accentuators and trapping agents  2.17 Describe the general sequence of most staining procedures  2.18 Define vital staining  2.19 Describe physical theories of staining  2.20 Describe chemical theories of staining  2.21 Describe metallic impregnation  2.22 Explain Metachromatic staining  2.23 Explain fluorescent staining  2.24 Define staining terminology  STAIN PREPARATION  Staining Solutions > Some stains and reagents are commercially prepared/available for purchase > Other stains are prepared in-house > Stock and working solutions are prepared following set procedures/protocols - similar to following a recipe > Quality control is maintained by testing new reagents/stains and also with every run  STORAGE AND HANDLING  Storing and Disposal of Stains and Reagents > All chemicals are to be properly labelled to include - Contents - Preparation Date/Expiry Date - WHMIS Labels - Storage Conditions - Precautions > All chemicals are to be stored as required (Ex. Flammables, Explosives, Oxidizers, etc..) > All chemicals are to be disposed of as per guidelines (Ex. Solvents) > Appropriate ventilation and PPE adhered to when handling staining solutions NATURAL AND SYNTHETIC DYES CLASSIFICATIONS OF DYE  Natural- plants, animals, insects  Synthetic- derived from benzene  Chromaphore group eg. C=C, C=N, C=O, N=N  Acid dyes have colored anions  Basic dyes have colored cations  Neutral- both acid and basic parts are colored MAKING THINGS OBVIOUS OR VISIBLE  Dyes or Stains  Chemical reactions  Metallic deposits DYE MOLECULE WHAT IS A CHROMAGEN?  The coloured part of a dye molecule.  The chromophore is found within the chromagen.  Auxochromes are side chains of the chromagen that bind chemically with a substrate. DEFINE CHROMAPHORE  An arrangement of atoms within a chromagen molecule that causes the compound to be coloured  Double bonds alternate with single bonds to form conjugated systems. Bonding electrons can move from one atom to another (resonance). These properties cause specific light absorption in the visible range. The result is coloured light transmission DEFINE CHROMOPHORE  Benzene is colourless to us  Visible in UV range