Zusammenfassung der Ressource
Test Your Own Genes
- Isolate Your DNA
- Amplify Your DNA By PCR
- Digest PCR Products With Restriction Enzyme HaeIII
- Analyze PCR Products By Gel Electrophoresis
- Determine Your PCR Genotype and Phenotype
- Results of gel electrophoresis
- Indicate heterozygous and homozygous dominant genotypes
- Heterozygous carriers have one dominant and one recessive allele
resulting in three bands because HaeIII cuts twice on the dominant
allele and none on the recessive allele. Though HaeIII cuts twice on
the dominant allele only two bands are shown for both alleles
because they are the same base pair length and therefore occupy
the same spot not the gel. Homozygous recessive individuals will
have a singular band because HaeIII didn't cut anywhere.
- Goal: Analyze electrophoresis results then
use PTC paper to determine if the gel
results match our phenotype
- Place the gel in the electrophoresis chamber and add buffer
- Lane 1: 20
microliters of
DNA marker
- Lane 2: 10 micrometers
of student 1 undigested
DNA
- Lane 3: 15 microliters
of student 1 digested
DNA
- Lane 4: 10 micrometers
of student 2 undigested
DNA
- Lane 5: 15 microliters of
student 2 digested DNA
- Let the gel run for at least 30 minutes then view with a white light box
- Goal: Run and stainless then view the results using a white light
box
- Label two tubes digested and undigested
- Transfer 15 microliters of PCR
product into the digested tube and
transfer the remaining amount into
the undigested tube
- Transfer the Haelll enzyme
directly into the digested tube and
pipet up and down to mix
- HaeIII recognizes the sequence
GGCC and cuts bluntly - perfect for
analysis because the DNA
fragments don't stick back
together
- Tap the bottom of the tube on a lab bench to mix and pool the
reagents
- Transfer the digested sample into a .2 ml
tube
- incubate at 37 degrees for one
hour
- Goal: Identify SNPs or
base pair differences
in the amplifies
sequence of TAS2R38
- Obtain a PCR tube with
the ready-to-go PCR
bead and label with
your initials
- Add loading dye,
place the tube on
ice, allow the bead
to dissolve
- The dye will turn
purple as the
bead dissolves
- Dye allows
use to see
the cheek
cells
- Place the PCR tube in a thermal cycler
- Store the amplified DNA on ice
- Goal: Use PCR to make
multiple copies of TAS2R38
gene for analysis
- Label a 1.5
microcentrifuge tube
with your intiials
- Pour all of the saline
solution into your
mouth and swish for
thirty seconds
- Spit the liquid into a paper cup
- Swirl the cup and
mix the cheek cells
then transfer to the
labeled
microcentrifuge
- Centrifuge
- Concentrates all the
DNA from the cheek
cells at the bottom
of the tube
- Pour off the supernatant
- Because it no
longer
contains any
cheek DNA
- Pipet up and down to
resuspend the pellet
- It spreads
the DNA
- Add chelex to
protect the cheek
cells from heat
- Heat the tube
- Releases the
DNA from the
nucleus
- Cell lysis
- When cool,
shake the tube
- Centrifuge
- Transfer
supernatant to a
labeled 1.5 tube
- The
supernatant
now contains
the DNA from
the cheek cells
and the pellet
contains debris
- Goal: Extract a sample of
cheek cells to start your
PCR reaction
- Goal: Use the DNA from
cheek cells to find an
individual's genotype for
PTC and compare these
results to the phenotype