Bio 11.1 Exercise 3D

Collection of Specimens
Fixation
Staining
Mounting
Storage

General Procedure for Slide Preparation: (C F S M S)

Collection of Specimens

• Must be collected as fresh as possible

• Can be parts or a whole organism

Fixation

• Specimen is chemically treated to induce rapid killing with minimal to no post-mortem changes.

• Specimen is usually put in a formaldehyde or glutaraldehyde solution for fixation.

Staining
Nucleus
Mordant
Counterstain
Crystal violet
Safranin red
Basic fuschin
Malachite Green
Hematoxylin
Eosin Y
Janus Green B
Methylene Blue

• Dyeing specific structures

• Primary Staining

  • Iodine (_)

  • _ - Helps primary stain stick to the structure.

  • _ - Stain used to dye other structures to emphasize the target structure

• Common dyes

  • _ - stains peptidoglycan in

    cell walls of bacteria violet

  • _ - Stains the cytoplasm

    red;

  • _ – stains the flagella pink/red.

  • _ - Bacterial Endospores

  • _ - stains the nucleus blue-violet or brown

  • _ – stains the cytoplasm pink/red.

  • _ – stains mitochondria

  • _ – stains the nucleus blue

Mounting

• Temporary _

  • Sample may be embedded or frozen in a supporting medium (water, waxes or resins).

• Permanent _

  • The specimen is subjected to increasing concentrations of ethanol (50% to 100%)

  • Treatment of resin and waxes

  • FOR LONG TERM STORAGE

Storage

• Slides are stored in a slide box.

• Slides must be properly labeled before storage.

Wholemount
Maceration
Smear
Section
Squash

Common Ways of Slide Preparation: (W M S S S)

Wholemount
Hydrilla leaf
Embryo
Planaria

• whole organisms or parts of organisms taken

• Preservation of external structure or for thin specimens (H_, E_, P_)

Maceration
Xylem
Tracheids in woody

• Use of acids and or physical shearing to tear apart the cells of a sample. (X_, T_)

Smear
Liquid
Blood
Bacterial Culture

• A drop of (_) specimen (B_, B_) is spread onto a slide then heated to a dry liquid and fix cells.

Section

• Cutting of the specimen into thin cells

• Used to observe tissue structure in plant and animal organs.

Squash
Chromosomes
Mitosis
Meiosis

• Studying _, karyotyping

• Used to observe _ and _.

Stages of Mitosis in onion root tip cells:

PMAT

Mitotic index

• describes the capacity of a group of cells to divide as well as their rate of cell division.

• total # of cells undergoing (PMAT) in the FOV / total # of cells in the FOV (Dividing and non dividing)