Testing for Familial Hypercholesterolemia
Caused by a Mutation in the LDLR Gene
A simulation of a genetic test using Gel Electrophoresis
Nature vs. NurtureNature = genes and their effects
Nurture = environmental influences
ExamplesSickle Cell Disease is heavily nature because it is related
to a specific gene that are inherited Hypercholesterolemia is a blend of Nature and nurture
Nature = genes such as APOB, PCSK9, LDLRAP1 and LDLR
Nurture = diet, exerciseMost traits are a combination of Nature and NurtureMost traits are controlled by many genesMost traits are effected my several environmental
influencers
Human GenomeWe have two in every cell!
Maternal and Paternal sources
Human Genome Complete set of human DNA About 3 billion base pairs Segmented into 23 different
sections called chromosomes23(egg) + 23(sperm) =
46(zygote) We have two of every gene.
Genes come in various forms.Ex: ‘wild type’ hemoglobin
and sickle cell hemoglobin
HypercholesterolemiaHigh cholesterol
High cholesterol leads to Coronary Artery Disease (CAD) which often results in heart attacks.
Our Lab This lab tests one of the genes (LDLR) associated with high
cholesterol Positive result means an 85% risk of heart attack for men in
there 40s and 50s or women in 50s or 60s Negative result means average risk of heart attack
Due to environmental factors (diet, exercise)
Background: Parents of Sylvia (2 yr old) both have high cholesterol. They want to know if it is related to their genes and if they passed the genes to their daughter. DNA samples have been collected from Mom, Dad and
Sylvia The LDLR gene in each of the samples have been amplified
and digested with a restriction enzyme. We will perform the gel electrophoresis procedure, analyze
the resulting gels and inform the parents of the outcome of the test and their daughters risk level of developing high cholesterol.
Day 1How to use a micropipette
Look at the number on the top of your micropipette
Look at the numbers on the side (through the window)
Push down the top “plunger” - feel first and second stopsFirst stop is for picking upSecond stop is for dispensing
Watch how to pick up a tip
Day 1How to use a micropipette
Watch how to pick up a liquidAlways hold the liquid in one hand while picking it
upONLY go to the first stop when picking up a liquid
Watch how to dispense a liquidAlways go to the first stop, then slowly to the
second stopPull micropipette out BEFORE releasing the
plungerWatch the technique
Day 1 - Practice Loading
ALWAYS use a TIP with your micropipette
ALWAYS keep the micropipette VERTICAL when you have liquid
1 l (micro) = 10-3 mL (milli) = 10-6 L
When picking up liquid, push to the FIRST stop only!
When dispensing liquid, push to the FIRST stop, then the SECOND stop
When dispending liquid, ALWAYS raise the tip out of the liquid before letting go of the button!
Day 2 - Loading/Running Gels
Only two group members at the gel at any given point
Each group member should load at least one sample
Load 35 L sample into the wells (label the wells on the diagram so you know where every sample is!) Tap the sample so that all is at the bottom of the container
Let me know once all samples are loaded
Work on the ‘paper lab’ activaty while you wait
Day 2 DNA samples Sample A – A known DNA sample called a “Standard” that
contains fragments of known length
Sample B – Control DNA that is known to have two normal copies of the LDLR gene
Sample C – Control DNA that is known to have two mutant copies of the LDLR gene
Sample D – Sylvia’s mom’s DNA
Sample E – Sylvia’s DNA
Sample F – Sylvia’s dad’s DNA
GroupsGroup 1 Group 2 Group 3 Group 4 Group 5 Group 6
Olivia Shanice Oliver Emma Liam
Patrick Suzanna Ashley Clara Alana
Jessica Marina Ethan Mei Yarden
Charles Jack Becca Mike
Day 3: Gel AnalysisPlace your gel on the light box
Do a detailed sketch of your Gel and the reference gel in your packet
Include in the sketch # and position of bands Band brightness Label the lanes
Use both gels when drawing conclusions about Sylvia.
Only one group at the light box at one time.
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