DNA Purification
Definition
 DNA purification is a
technique that removes
impurities and unused
reagents from samples
after enzymatic
reactions, such as PCR
Before (b)
and after (a)
DNA
purification
DNA
Impurities
www1.qiagen.com
Quick Quiz
The purpose(s) of DNA purification is to:
A. Remove excess reagents remaining from PCR
B. Remove sample impurities
C. Prepare the sample for downstream applications
(i.e. sequencing)
D. All of the above
Non-examples
 DNA purification is not used to…
 Isolate DNA from intact cells
 Change the concentration of DNA in a given
volume
 Purify protein or RNA samples
Downstream Applications
 Purified PCR products may be used in the
following types of reactions…
 Additional PCRs
 Sequencing
 Restriction digestion
 Ligation and
transformation (Cloning)
 Labeling or hybridization
Qiagen PCR Purification
Mix sample and buffer.
Makes DNA in solution ready to bind column.
Load onto column. Nucleic acids bind
to membrane. Other components flow through.
Wash Column. Removes any contaminants.
Elute DNA. DNA releases from column
and is ready for downstream applications.
Quick Quiz
In column purification, DNA is bound to the column
membrane using a ______ salt solution.
DNA is eluted off the membrane using a ______ salt
solution.
A.
B.
C.
D.
High, low
Low, high
Iodized, non-iodized
Saturated, supersaturated
Quick Quiz
Which list of activities is in the correct order?
A. DNA extraction, DNA purification, PCR, DNA
sequencing
B. DNA purification, DNA extraction, PCR, DNA
sequencing
C. DNA extraction, PCR, DNA purification, DNA
sequencing
D. DNA extraction, PCR, DNA sequencing, DNA
purification
END
Resources
Modified QIAquick protocol: “PCR
Purification” handout
Qiagen QIAquick PCR purification
protocol
California State Chemistry Standards
Grade 8
6c. Living organisms have many different kinds of molecules…
Grades 9-12
6. Solutions are homogenous mixtures of two or more
substances
7. Energy is exchanged or transformed in all chemical
reactions and physical changes of matter
8. Chemical reaction rates depend on factors that influence the
frequency of collision of reactant molecules
California State Biology Standards
Grade 7
2e. DNA is the genetic material of living organisms and is
located in the chromosomes of each cell
3a. Genetic variation and environmental factors are causes of
evolution and diversity of organisms
Grades 9-12
2. Mutation and sexual reproduction lead to genetic variation in
a population
7. The frequency of an allele in a gene pool of a population
depends on many factors and may be stable or unstable over
time
California State
Investigation and Experimentation
Standards
Grades 7, 9-12
a/b. Select and use appropriate tools and technology to perform
tests, collect data, analyze relationships, and display data
Grade 8
a. Plan and conduct a scientific investigation to test a hypothesis
National Standards
Grades 6-12
Content Standard A: Science as Inquiry
Content Standard C: Life Science
Content Standard E: Science and Technology