U4 LAB: ELECTROPHORESIS Flashcards
Process of separating the charged constituents of a sample by means of an electrical current
Electrophoresis
Movement of charged particles through a _____ medium in a _______ buffer
solid, liquid
2 main components of Electrophoresis chamber
- Chamber
- Power Source
Tank-like, where solid media and liquid buffer is placed
Chamber
This supplies the electric current to the anode area
Power Source
Positively charged pole, attracts negative particles
Anode (red)
Negatively charged pole, attracts positive particles
Cathode (block)
Flow of electric current
Cathode > Anode > Power Source
Electrophoresis is used to separate?
negatively charged particles
Functional group molecule in which at least one has a positive electrical charge, based on isoelectric point
zwitterion
Gel is commonly made up of?
Agarose
Gel used in Protein Electrophoresis
Polyacrylamide gel
The Electrophoresis run is dependent on the?
voltage used, and time
DNA will be separated based on?
molecular weight
Farther travels on gel
Lighter DNA
Harder to travel
Heavier DNA
Has a net charge that can be either positive or negative depending on pH conditions
Amphoteric
Movement of buffer ions & solvent relatives to the fixed support
Electroendosmosis / Endosmosis
Migration of small charged ions
Iontophoresis
Five components of Electrophoresis
- driving force
- support medium
- buffer
- sample
- detecting system
Support Media
- cellulose acetate
- agarose gel
- polyacrylamide gel
When utilizing electrophoresis for DNA observation, what stain must be used?
Ethidium Bromide (shaken then swirled)
This is added in order to track the migration of analyte across the gel.
Tracking dye
T/F: The tracking dye migrates ahead of the bond or the electrolyte of interest that you are trying to separate.
True
T/F: The electrophoretic run can continue even if the tracking dye nears the end of the gel.
False!
Some manufacturers include what in their tracking dyes?
glycerol
Common Tracking Dye
Cotton Phenol Blue
Radioactive dye used to visualize DNA
Detection Dye
Alternative fluorescent dye to EtBr and now often used
Gel Red
This will give proteins the net electric (negative) charge that allows them to move from cathode to anode.
Buffer
Detection system
UV transilluminator
Gel must be viewed in?
Gel Documentation Viewer
Unit used in electrophoresis
Base pairs
This will serve as reference to know how many base pairs your DNA is.
DNA ladder
Left side of the gel contains?
DNA of known base pairs
Increment of DNA ladder
50 (Start from 50, 100, 150, 200 and so on)
The closer the sample is to the well, the _____ it is
heavier
Farther the sample, the lighter
Electrophoresis can be used for?
quantification to see if there is a DNA fragment
Why is Ethidium Bromide the best stain for DNA extraction?
intercalation or insertion between layers
Amount of buffer needed is dependent on?
size of chamber
Five Steps of Electrophoresis
- Loading of patient sample
- Electrophoretic migration
- Wash and fix
- Staining
- Visualization (Qualitative)
- Quantification
Fractions of Separated Proteins
- Albumin
- Alpha 1
- Alpha 2
- Beta
- Gamma globulins
Stains for Bands
- Amido Black
- Ponceau S
- Oil Red O
- Sudan Black
- Fat Red 7B
- Coomassie Blue
- Gold/Silver Stain
Lower voltage for _____ periods of time
longer
Higher voltage for _____ periods of time
shorter