Microarray introduction
Do now
Explain how a microarray uses hybridization to test many genes at once and where it differs from PCR.
- Hand in
- Three-row method comparison table (PCR, gel, microarray) plus one sentence on a microarray limit not shared by the other two methods.
- Where
- Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
You get two school days for every day you were absent, so this deadline moves with you.
PCR and a gel handle one target at a time. How does a chip the size of a stamp test thousands of genes in a single run?
Explain how a uses to test many genes at once and where it differs from PCR.
- • You'll be able to explain how a reads many genes by .
- • You'll be able to compare PCR, gel, and by purpose and limit.
- What does it mean for two single DNA strands to be complementary?
- On a , does a bright spot mean a gene is expressed or not expressed?
- 1Define and explain how a labeled sample binds to spots on a .
- 2Describe what a colored spot versus a dark spot tells you about a gene.
- 3Compare in one row each: PCR, gel, and , listing what each method is best for.
- 4Write one limit of microarrays that gel or PCR does not share.
- 5Submit your method comparison as your daily evidence.
What did this day actually feel like?
Microarray introduction
Thousands of expression measurements at once instead of one gene at a time. The scale is the point and also the problem, because with that many measurements some will look significant by chance.
AT HOME, THE NIGHT BEFORE WED OCT 21 Methods quiz Quiz on the methods so far. This is where the fifteen minutes a night either paid off or did not. For me it mostly did.
Turned in: WebXam practice → recorded in Class Records
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
The same day, drawn.
Thousands of expression measurements at once instead of one gene at a time. The scale is the point and also the problem, because with that many measurements some will look significant by chance.
Fiction. There is no such student. The lessons, labs and dates are the real planned course; the student, the classmates and the conversations are invented.
🛠 Get unstuck · pick your level
🔑 Today's words · 5
Tap a word in the lesson for a plain meaning and one example. Recycled into next week's Do-Now.
Do the work · 80-minute blockfirst 5 min = hook▸
💡 Big idea: A reads fluorescence where sample DNA hybridizes to matching probes, so one chip can report the expression of thousands of genes at once.
- 0-8Hook: image; introduce concept
- 8-25Define ; explain spot color as expression signal
- 25-50Build comparison table: PCR, gel, (purpose, scale, limit, output)
- 50-65Write one limit of microarrays not shared by PCR or gel
- 65-75Partner quiz: cover one column; name the method from description
- 75-80Submit comparison table to the class site; review for Friday quiz
- • Hook: Show a image and ask: how many tests do you think this represents? (answer: tens of thousands).
- • Why it matters: Microarrays accelerated genomics by shifting from one-gene-at-a-time to genome-wide profiling.
- • Today's work: You build a comparison table that will be your study reference for Friday's quiz.
- • Exit goal: Method comparison table with one limit submitted before the bell.
- • : fluorescently labeled cDNA from a sample binds to complementary probe sequences on the chip; fluorescence indicates which genes are expressed.
- • A bright spot means the gene is expressed (mRNA present in sample); a dark spot means little or no expression.
- • Microarrays survey thousands of genes at once but require specialized equipment and bioinformatics; PCR is targeted and gel is the readout, not a scanner.
PCR, restriction enzymes, electrophoresis, microarrays, and the limits of each method. · introduction
Day 4 of this lesson. Open this exact section in myPLTW (find it in Clever, Microsoft sign-in), then do the work below.
Do this: Open Activity 3.1.4 DNA in myPLTW and build your PCR-gel-microarray method comparison table.
Mark the activity complete after your comparison table is submitted.
Gel should be done (Wednesday); method comparison table due today.
Three-row method comparison table submitted on the class site.
The official PLTW activity stays inside myPLTW. If myPLTW will not open, use F1 and E1-E3 on this page to complete today's local evidence decision, then make up the official activity when access returns. Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not.
Check things off as you work, then submit. This tells Mr. Mendoza how you're doing so he can help the class. It does not replace turning in your producible through the submission route shown below.
Use the code Mr. Mendoza gave you, not your name. Saved on this device.
PCR, restriction enzymes, electrophoresis, microarrays, and the limits of each method. · Microarray introduction
Open Activity 3.1.4 DNA in myPLTW and build your PCR-gel-microarray method comparison table.
Gel should be done (Wednesday); method comparison table due today.
This is how Mr. Mendoza sees the class keeping pace with PLTW. Be honest, it only helps if it is accurate.
🎯 Explain how a uses to test many genes at once and where it differs from PCR.
- Define and explain how a labeled sample binds to spots on a .
- Describe what a colored spot versus a dark spot tells you about a gene.
- Compare in one row each: PCR, gel, and , listing what each method is best for.
- Write one limit of microarrays that gel or PCR does not share.
- Submit your method comparison as your daily evidence.
Vocabulary task: Three-row method comparison table (PCR, gel, ) plus one sentence on a microarray limit not shared by the other two methods.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Use the checklist just below and upload by 11:29 PM for full credit. Absent with an excused absence? You get two school days for every day you were absent, so this deadline moves with you.
| Task | Who |
|---|---|
| Define and explain how a labeled sample binds to spots on a . | _______ |
| Describe what a colored spot versus a dark spot tells you about a gene. | _______ |
| Compare in one row each: PCR, gel, and , listing what each method is best for. | _______ |
| Write one limit of microarrays that gel or PCR does not share. | _______ |
| Submit your method comparison as your daily evidence. | _______ |
Working solo? Put your own name in "Who" for every row.
- You'll be able to explain how a reads many genes by .
- You'll be able to compare PCR, gel, and by purpose and limit.
- 1Do thisExplain how a microarray uses hybridization to test many genes at once and where it differs from PCR.
- 2Use this resource
- 3Submit thisVocabulary task: Three-row method comparison table (PCR, gel, microarray) plus one sentence on a microarray limit not shared by the other two methods.
- 4Submit it here
- 1Open the drop folder.
- 2Sign in with your district Microsoft account, not a personal one.
- 3Upload the file, named Lastname_Firstname__Assignment Title.
- 4Your own upload panel says Uploaded with a green check: that is your receipt.
Turn this in at the drop folder with your district Microsoft sign-in, or hand it to Mr. Mendoza in class. Both count as submitted. Doing the activity in myPLTW does not. Genetics of Disease (Medical Interventions) › PCR, restriction enzymes, electrophoresis, microarrays, and the limits of each method. › Vocabulary taskOpen the drop folder
Learn it · deck, reading, and vocabulary▸
The deck carries the prior idea forward, lets you inspect an analogy, maps the rule to biology, and ends with the same evidence decision and exit ticket used on this page.
Generated from this lesson's canonical data with a red-team citation check.
acts as a sieve and DNA is pulled by charge, so smaller fragments travel farther and band position becomes a readable size map.
A reads fluorescence where sample DNA hybridizes to matching probes, so one chip can report the expression of thousands of genes at once.
A library keeps a master plan protected while working copies guide production at different stations.
- Why protect the master copy?
- What information moves?
- Where can an error change the final product?
Stored information can be copied, read, and converted into a functional product.
Genes are regulated biological sequences, not conscious instructions, and one gene rarely determines a whole trait alone.
- • Master plan maps to DNA.
- • Working copy maps to RNA.
- • Production output maps to or a regulated cell function.
Driving question: PCR and a gel handle one target at a time. How does a chip the size of a stamp test thousands of genes in a single run?
What you already know: acts as a sieve and DNA is pulled by charge, so smaller fragments travel farther and band position becomes a readable size map.
New idea: A reads fluorescence where sample DNA hybridizes to matching probes, so one chip can report the expression of thousands of genes at once.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Microarray introduction. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled testing, treatment, or biological process and identify where evidence limits the decision.
- Observe or measure the relevant feature in introduction.
- Organize the observation with a stable evidence ID.
- Apply this rule: Stored information can be copied, read, and converted into a functional product.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: PCR and a gel handle one target at a time. How does a chip the size of a stamp test thousands of genes in a single run?
What the evidence supports: E1-E3 and F1 support the daily take-home when the response meets the stated success criteria.
What it cannot prove: The package does not support claims beyond this lesson's or any real patient diagnosis.
- • : A short single strand of DNA that binds to a target sequence and gives DNA polymerase a starting point to build a new strand, as in PCR.
- • : A that recognizes a specific and cuts the strand there, a key tool for cutting and studying genes.
- • : A lab technique that uses an electric current to pull DNA or fragments through a gel, separating them by size.
- • : A chip holding thousands of tiny DNA spots that lets scientists measure the activity of many genes at once by detecting which spots light up.
- • : The pairing of two single DNA or RNA strands with matching base sequences into a double strand, used in tests to detect a specific gene.
- • marker: A measurable feature, molecule, or gene used to identify a cell, organism, or condition, like a flag that signals something specific.
Use it now: Choose one decision option. Cite E1 and E3, then explain how the rule connects the evidence to your choice.
Go further, optional: The source links below are optional enrichment. Every fact required for today's local evidence decision appears in this lesson package.
: fluorescently labeled cDNA from a sample binds to complementary probe sequences on the chip; fluorescence indicates which genes are expressed.
Limit: E1 supplies context or an observation; it does not by itself establish the explanation.
A reads fluorescence where sample DNA hybridizes to matching probes, so one chip can report the expression of thousands of genes at once.
Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.
You'll be able to explain how a reads many genes by .
Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.
PLTW-GEND-2026-10-20 · Simulated classroom evidence scenario
Your role: medical interventions team member
Decision: Your team must decide what the evidence from introduction supports before submitting the vocabulary application named on the lesson page.
- • Choose the strongest supported explanation.
- • Choose the next evidence to collect.
- • Hold the decision because the evidence is insufficient.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the vocabulary application.
Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about introduction. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
Mean = sum of values / number of values. Median = middle ordered value. Range = maximum - minimum.
For 2, 4, 4, and 10: mean = 20 / 4 = 5, median = 4, and range = 10 - 2 = 8.
Mean, median, and range keep the measurement unit. Order the values before finding the median.
Calculate the requested summary for today's supplied values, then write what it reveals and what it hides.
Students often think Students often think a is just a faster version of a gel, or that the colored spots show the size of DNA fragments the way gel bands do.. The trap: A does not measure size at all. Its spots report which genes are expressed based on where labeled sample binds by complementary . Confusing it with a gel means you miss that a microarray answers what is expressed, not how big the fragment is.
Hybridization in my words: A microarray is covered with single-stranded probe sequences. A labeled sample of DNA or cDNA washes over it, and each piece sticks (hybridizes) only where it finds its complementary probe. A bright, colored spot means that gene's sequence was present in the sample; a dark spot means it was not.
Method comparison: I compared PCR, gel, and microarray by what each is best for.
Microarray limit not shared by the others: A microarray needs specialized scanning equipment and bioinformatics software to read thousands of spots, while a PCR product or a gel can be set up and read with much simpler tools.
| Method | Best for | Output |
|---|---|---|
| PCR | Amplifying one target sequence | Many copies of one region |
| Gel | Separating fragments by size | Bands showing fragment sizes |
| Microarray | Surveying thousands of genes at once | Spot pattern showing expression |
This model shows the level of evidence and organization needed to complete: Completes the methods comparison: a three-row table contrasting PCR, gel, and microarray by purpose plus one sentence on a microarray limit the others do not share.
- Define the term in plain scientific language.
- Connect it to the current investigation.
- Use it accurately in a new example or contrast.
Keep the structure. Replace the question, facts, measurements, and evidence. Then recheck units, vocabulary, and whether the conclusion goes beyond the evidence.
Also due today: Submit your comparison table to the class site.
- CER:
- Claim, Evidence, Reasoning: make a claim, back it with evidence, explain your reasoning.
- SOP:
- Standard Operating Procedure, the exact steps to follow (especially in a lab).
- Tracker:
- Your PLTW progress log where you record completed evidence.
- myPLTW:
- The PLTW course site where you do the online activities. Find it in Clever with your Microsoft sign-in, right next to Schoology.
Tap the speaker to hear a term. Add two of these to your notebook glossary with a definition and an example in your own words.
Pick just 2 or 3 words from today and make them yours: write what each one means in your own words, name the context clue or evidence that helped, then give one example from what you actually did in Microarray introduction. Try your own words first; the glossary is there if you get stuck. This is voluntary and counts as extra credit, so keep it short.
Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.
Classroom documents for this lesson are posted in Schoology. Open Clever, then Schoology, and find each one by the name shown on its card.
Open this when the class reaches this activity and use it to complete the required lesson artifact.
Placement rationale
Matched PCR, , microarrays by path:Medical-Interventions/Unit-2_How-to-Screen-Your-Genes/2.1_Genetic-Testing-and-Screening; keywords:pcr, gel electrophoresis. Score 142. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
Use this if you were absent, got stuck, or need another pass before you submit the lesson artifact.
Placement rationale
Matched PCR, , microarrays by path:Medical-Interventions/Unit-2_How-to-Screen-Your-Genes/00_Unit-Overview; keywords:pcr, gel electrophoresis. Score 138. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
Use this after the required lesson work when you are ready for a harder application or a deeper connection.
Placement rationale
Matched PCR, , microarrays by path:Medical-Interventions/Unit-2_How-to-Screen-Your-Genes/2.1_Genetic-Testing-and-Screening; keywords:gel electrophoresis. Score 134. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
How to get there: open Clever and sign in with your Microsoft (district) account. Both myPLTW and Schoology are in Clever. Do the activity in myPLTW. Turn the work in on this site or hand it to Mr. Mendoza, because that is the step that counts as submitted. Schoology only shows your report-card grade later.
Check yourself · commit, then reveal▸
Claim ceiling for this check: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about introduction. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
On a microarray, a spot for a gene glows bright. What does that tell you about that gene in the sample, and what does the brightness come from?
Write an answer and pick a confidence to unlock the key.
Fast retrieval with instant answers, not the commit-then-reveal check above. Try each from memory first: write what you remember about the earlier units, then check yourself here.
Go further and get help▸
What today's skills lead to. These are real health-science careers this course builds toward. Tap one to see, on the US Department of Labor's O*NET site, what the job actually involves, what it pays, and how fast it is growing.
Use to test how conserved IRF6 is across humans, mice, and zebrafish.
Goes with: BLAST: is IRF6 conserved across species?
Search ClinVar for which IRF6 changes are known to cause disease.
Goes with: ClinVar: which IRF6 changes cause disease?
The bench work needs equipment you do not have at home. Do the thinking half now: read the procedure, write your prediction, and set up your data table so it is ready.
Back in class. Ask Mr. Mendoza for the class data set, or for a bench slot to run it yourself. Do not submit a Vocabulary task with invented numbers.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
Genetic Science Learning Center: Gel Electrophoresis- CompleteEvery required part of the artifact is present, nothing left blank.
- AccurateThe science and the data are correct and match the evidence.
- Scientific reasoningYou explain your claim with evidence and reasoning (CER), not just an answer.
- Professional communicationClear, organized, labeled, and written the way a clinician or scientist would.
- SubmittedTurned in the right way, on the class site or handed to Mr. Mendoza in class, and confirmed. Not in Schoology: that is where the report-card grade appears later.