Stains in MeTHOD pREATICAL Flashcards
What is Vivo Staining ?
the process of dyeing living tissues— in vivo means “in life” (compare with in vitro
staining).
How does it work ?
It works by letting certain cells or structures take on contrasting color(s), their form (morphology) or position within a cell or tissue can be readily seen and studied
It involves colouring cells or structures that are no longer living. .
What is the actual purpose ?
reveal cytological details that might otherwise not be apparent;
however, staining can also reveal where certain chemicals or specific chemical reactions are taking place within cells or tissues.
How are cells/Slides prepared ?
Permeabilization - treatment of cells, generally with a mild surfactant, which dissolves cell membranes in order to allow larger dye molecules to enter inside the cell.
• Fixation - serves to “fix” or preserve cell or tissue morphology through the preparation process.
but most fixation procedures involve adding a chemical fixative that creates chemical bonds between proteins to increase their rigidity.
What are common stains for fixation ?
Common fixatives include formaldehyde, ethanol, methanol, and/or picric acid.
What are some procedure in preparing sample ?
Mounting - involves attaching samples to a glass microscope slide for observation and analysis.
Staining - application of stain to a sample to color cells, tissues, components, or metabolic processes.
What is Bishmark Brown ?
Staining - application of stain to a sample to color cells, tissues, components, or metabolic processes.
List some stains and their function ?
Iodine - used as a starch indicator. When in solution, starch and iodine turn a dark blue color.
- Malachite green - a blue-green counterstain to safranin in Gimenez staining for bacteria. This stain can also be used to stain spores.
- Methylene blue - stains animal cells to make nuclei more visible.
Name one stain and its function ?
Ethidium bromide - this stain colors unhealthy cells in the final stages of apoptosis, or deliberate cell death, fluorescent red-orange.
- stains nuclei red and may be used on living cells.
Neutral/Toluylene red
Nile red/Nile blue oxazone
this stain is made by boiling Nile blue with sulfuric acid, which creates a mix of Nile red and Nile blue. The red accumulates in intracellular lipid globules, staining them red. This stain may be used on living cells.
Osmium tetroxide
- used in optical microscopy to stain lipids black.
Rhodamine -
a protein-specific fluorescent stain used in fluorescence microscopy. Muntjac skin fibroblast labeled with rhodamine phalloidin
Safrani
a nuclear stain used as a counterstain or to color collagen yellow.
Indirect Fluorescent Staining Methods
• This approach requires only the primary antibody
This approach requires only the primary antibody and a fluorphore-conjuated secondary antibody, and is the simplest form of signal amplification.
What is Tissue preservation ?
aggregate of cells is kept alive outside of the organism from which it was derived
Dyes
used whenever cell and tissue components in animal and plant material have to be visualized.
Microscopy dyes
used mainly in histology, cytology and microbiology but also in analyzing textile fibres, paper and other technical products.
What is vivtro staining ?
involves colouring cells or structures that are no longer living.
Certain stains are often combined to reveal more details and features than a single stain alone.
Combined with specific protocols for fixation and sample preparation, scientists and physician
What is Permeablization ?
treatment of cells, generally with a mild surfactant, which dissolves cell membranes in order to allow larger dye molecules to enter inside the cell.
What is fixation and what does it involve ?
Fixation - serves to “fix” or preserve cell or tissue morphology through the preparation process.
This process may involve several steps, but most fixation procedures involve adding a chemical fixative that creates chemical bonds between proteins to increase their rigidity.
• Common fixatives include formaldehyde, ethanol, methanol, and/or picric acid.
