PACK 2026 CORRECT SOLUTIONS GRADED
A+
⩥What is gel electrophoresis. Answer: the separation of materials based
on size and migration patterns when subjected to electrical forces in a
resistive medium.
⩥which direction does the DNA flow in gel electrophoresis. Answer:
due to DNA being negatively charged, it will migrate towards the
positive end
⩥What determines how far the DNA will travel in a gel. Answer: the
size of the DNA fragment
⩥What factors affect migration of smaples within a gel. Answer: buffer
concentrations
gel make up
physical factors
time
electric current
,⩥What is agarose gel electrophoresis. Answer: most common gel-
polysaccharide extracted from seaweed- concentrations are varied with
the size of DNA trying to be separated
larger DNA size = lower concentrations of agar (.5%=1%)
smaller DNA size = higher concentrations (2%-3%)
⩥What is Polyacrylamide gel electrophoresis. Answer: used for the
resolution of very small DNA segments (PAGE). Can detect 1bp
differences in segments.
Is chemically prepared and catalyzed into the gel
Pore size is easily adjusted during gel preparation for custom gels to
particular experiments
⩥What is Pulse Field Gel Electrophoresis. Answer: for resolution of ver
large pieces of DNA 50k +
Along with specific gel and buffer combinations the electrical field is
pulsed or alternated in various directions/dimensions to facilitate
movement of large pieces
Fled inversion gel electrophoresis is the most common PFGE and is
achieved by switching the anode and cathode periodically for repeated
forward and back movements of the fragments to gain resolutions.
Variations occur at 90 deg to normal electron flow, in circular patterns
⩥what is capillary electrophoresis. Answer: mostly used for the
separation of chemicals and multicompound molecules.
, ⩥Describe capillary electrophoresis. Answer: A sample is dissolved in
buffer
Buffer systems are charge dand connected via a glass capillary
smaller negatively charged objects travel faster than large positive
charged ones.
Fluorescent light is sent through a window in the capillary and a detector
measures absorbance as objects pass
When used for nucleicc acid the DNA must be completely denatured
(single stranded) the capillary is held at denaturing temperatures and
dissipates heat well
Very small volumes of DNA and when subjected to high currents the
small fragments are detected first
⩥What are the types of blotting. Answer: Southern blot
Northern Blot
Western blot
Southwestern Bot
Eastern Blot
Far Eastern blot
⩥Describe a southern blot. Answer: Target: DNA
Probe: Nucleic Acid
Purpose: Gene structure