WET LAB DNA Barcoding: From Samples to Sequences - Northwest ...

WET LAB
Wet Lab: Slide #3
Lysis or “to lyse”: To break open.
Proteinase K: Type of enzyme that breaks
down proteins, including nucleases.
Nuclease: Type of enzyme that breaks
down nucleic acids.
5. Show Slide #4, “DNA Purification Using ‘Spin Columns,’” which reviews the
steps in DNA purification once again, with added visuals and more details
about the laboratory protocol. The materials used are called “spin columns”
because scientists use a microfuge to “spin” the DNA-binding columns and
speed the DNA purification process. Review these steps with students:
a. Day 1: Lyse your sample (break open the cells). This step involves adding
to your sample a lysis solution and proteinase K, an enzyme that breaks
down other proteins. This is mixed in nuclease-free water. Nucleasefree
water (such as distilled or nano-pure water) contains no enzymes
(nucleases) that would break down DNA. The mixture is then heated
to aid the digestion process, as proteinase K activity increases at higher
temperatures.
b. Day 2: Add your sample to the spin column to bind the DNA to the membrane.
c. Wash away the cell debris with a wash solution. For this experiment,
students will perform two wash steps – one with a pre-wash solution,
and one with a wash solution.
d. Elute your DNA in buffer.
6. Pass out Student Handout—DNA Purification for DNA Barcoding and have
students work through the activity in small groups of up to 4 students each.
Enzyme: A type of protein that catalyzes
(increases the rate of) chemical reactions.
For example, ATP synthase is an enzyme
that catalyzes or facilitates the creation
of ATP.
Nuclease-free water: Water that does
not contain nucleases. Often this water
has been subjected to multiple rounds
of purification, including being passed
through a nano-filter. It is sometimes
referred to as “nano-pure” or “ultra-pure”
water, as it should contain only H 2
O, with
no dissolved salts or other contaminants.
Buffer: A substance used to stabilize or
maintain the pH of a solution.
Wet Lab: Slide #4
Wet Lab – DNA Barcoding: From Samples to Sequences
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©Northwest Association for Biomedical Research—Updated October 2012