Antigen-antibody and ELISA model
Safety gate · before any work
- Goggles and gloves required for the full model run even with food-coloring solutions.
- Students must follow the labeled well layout exactly; switching wells invalidates the standard curve comparison.
- Dispose of used pipette tips in the designated waste container, not loose in the trash.
Do now
Explain how antigens and antibodies bind and run a model ELISA to see how that binding produces a signal.
- Hand in
- Model ELISA data table: well ID, observed color, and assigned concentration from standard curve; positive result identified and explained.
- 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.
In the model, well after well develops color at different strengths. How does the lock-and-key fit between one and one let that color mean 'this exact target is here, this much of it'?
Explain how antigens and antibodies bind and run a model to see how that binding produces a signal.
- • You will be able to explain - specific binding.
- • You will be able to describe how an turns binding into a signal.
- • You will be able to read a model against a .
- In your own words, what does it mean that an is 'specific' to one ?
- In the model, a well turns a deep color. Does that mean a lot of the target was there or a little? Why?
- 1Draw an and its matching and label the specific binding site.
- 2Read how an uses that binding plus a color reaction to detect a target.
- 3Run the model with your dilution series, recording color at each well.
- 4Match each well's color to a concentration using your .
- 5Identify which model well represents a positive result and explain why.
- 6Write one sentence on how specificity makes the test trustworthy.
What did this day actually feel like?
Antigen-antibody and ELISA model
The sandwich: capture antibody, antigen, detection antibody, then something that produces colour. Specificity comes from the antibody only binding its target.
We modeled it dry before touching reagents, which meant Wednesday next week was checking rather than guessing.
Turned in: data table → Data Tables folder
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.
The sandwich: capture antibody, antigen, detection antibody, then something that produces colour. Specificity comes from the antibody only binding its target.
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
Lab day: Tier 1 is the whole class at the bench. No extension today.
🔑 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: An binds only its specific , so the color it produces reliably signals that exact target and how much of it was present, which is what makes the a trustworthy diagnostic.
- 0-10 minDraw - diagram in notebook; label antigen, antibody, and specific binding site
- 10-20 minRead the mechanism: binding, link, color reaction; summarize in two sentences
- 20-55 minRun the model : apply dilution series to labeled wells; record color in each well as it develops
- 55-65 minUse the to assign a concentration to each well color; record in
- 65-73 minIdentify the positive result well and explain why it represents a positive in writing
- 73-80 minWrite the specificity sentence; compare with a partner and resolve any discrepancies
- • Every HIV test, every COVID test, every pregnancy test uses the same antibody-binding principle you are about to run.
- • The model uses food coloring to simulate the color reaction so the concept is visible without hazardous reagents.
- • Your pre-lab work from Wednesday is your net; follow the labeled layout and numbered steps exactly.
- • Exit goal: a complete of well colors matched to concentrations using your .
- • Antibodies bind only to their specific at the binding site; this lock-and-key specificity prevents cross-reactions.
- • In an , binding is coupled to an -linked color reaction: more bound means stronger color signal.
- • The converts a color intensity reading into a quantitative concentration.
Concentration, serial dilution, standard curves, antigen–antibody binding, direct vs. indirect ELISA. · - and model
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 1.1.5 (protocol and results) in myPLTW and begin setting up your standard-curve .
Complete the standard-curve using your dilution series concentrations.
diagram should be done (Wednesday); standard-curve table due today.
Standard-curve with concentrations and signal values in notebook.
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.
Concentration, serial dilution, standard curves, antigen–antibody binding, direct vs. indirect ELISA. · Antigen-antibody and ELISA model
Open Activity 1.1.5 (protocol and results) in myPLTW and begin setting up your standard-curve .
diagram should be done (Wednesday); standard-curve 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 antigens and antibodies bind and run a model to see how that binding produces a signal.
- Draw an and its matching and label the specific binding site.
- Read how an uses that binding plus a color reaction to detect a target.
- Run the model with your dilution series, recording color at each well.
- Match each well's color to a concentration using your .
- Identify which model well represents a positive result and explain why.
- Write one sentence on how specificity makes the test trustworthy.
Data table: Model : well ID, observed color, and assigned concentration from ; positive result identified and explained.
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 |
|---|---|
| Draw an and its matching and label the specific binding site. | _______ |
| Read how an uses that binding plus a color reaction to detect a target. | _______ |
| Run the model with your dilution series, recording color at each well. | _______ |
| Match each well's color to a concentration using your . | _______ |
| Identify which model well represents a positive result and explain why. | _______ |
| Write one sentence on how specificity makes the test trustworthy. | _______ |
Working solo? Put your own name in "Who" for every row.
- You will be able to explain - specific binding.
- You will be able to describe how an turns binding into a signal.
- You will be able to read a model against a .
- 1Do thisExplain how antigens and antibodies bind and run a model ELISA to see how that binding produces a signal.
- 2Use this resource
- 3Submit thisData table: Model ELISA data table: well ID, observed color, and assigned concentration from standard curve; positive result identified and explained.
- 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) › Concentration, serial dilution, standard curves, antigen–antibody binding, direct vs. indirect ELISA. › Data tableOpen 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.
A repeats the same known at each step, so it builds a ladder of exactly-known concentrations you can later use to measure an unknown.
An binds only its specific , so the color it produces reliably signals that exact target and how much of it was present, which is what makes the a trustworthy diagnostic.
A smoke alarm detects signs of fire but can also react to burnt toast.
- What does the alarm detect?
- What creates a false alarm?
- What evidence is needed before declaring a fire?
A screening signal changes what to investigate next; it does not automatically prove the cause.
Biomedical tests have measured performance and biological sampling limits that a household alarm does not capture.
- • Alarm signal maps to a test result.
- • Burnt toast maps to a .
- • Inspection maps to confirmation or the next test.
Driving question: In the model, well after well develops color at different strengths. How does the lock-and-key fit between one and one let that color mean 'this exact target is here, this much of it'?
What you already know: A repeats the same known at each step, so it builds a ladder of exactly-known concentrations you can later use to measure an unknown.
New idea: An binds only its specific , so the color it produces reliably signals that exact target and how much of it was present, which is what makes the a trustworthy diagnostic.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Antigen-antibody and ELISA model. 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 - and model.
- Organize the observation with a stable evidence ID.
- Apply this rule: A screening signal changes what to investigate next; it does not automatically prove the cause.
- Choose the option the evidence supports and state the limit of the conclusion.
Real biomedical example: In the model, well after well develops color at different strengths. How does the lock-and-key fit between one and one let that color mean 'this exact target is here, this much of it'?
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 molecule, often on a germ's surface, that the immune system recognizes as foreign and responds to by making matching antibodies.
- • : A Y-shaped made by the immune system that binds to a specific foreign target, marking it for destruction or blocking its effect.
- • : A lab test that uses antibodies linked to an to detect and measure a specific , with a color change signaling its presence.
- • : A stepwise process of repeatedly diluting a sample by the same factor to make a range of lower, known concentrations.
- • : A graph made from samples of known concentration, used to read off the unknown concentration of a test sample from its measured signal.
- • : The specific molecule an acts on, fitting into the enzyme's active site so it can be changed into a product.
- • : A measure of how much light a sample blocks at a given wavelength, used to estimate how concentrated a substance is in a solution.
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.
Antibodies bind only to their specific at the binding site; this lock-and-key specificity prevents cross-reactions.
Limit: E1 supplies context or an observation; it does not by itself establish the explanation.
An binds only its specific , so the color it produces reliably signals that exact target and how much of it was present, which is what makes the a trustworthy diagnostic.
Limit: E2 is a teaching statement or comparison and must be checked against the task evidence.
You will be able to explain - specific binding.
Limit: E3 supports only the result or product criterion named here; it cannot justify a broader clinical or causal claim.
PLTW-GEND-2026-09-17 · Simulated classroom evidence scenario
Your role: medical interventions team member
Decision: Your team must decide what the evidence from - and model supports before submitting the labeled and result claim named on the lesson page.
- • Keep the current design.
- • Revise the feature that misses a criterion.
- • Run one more fair test before choosing.
Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the labeled and result claim.
Claim ceiling: The supplied lesson evidence can support an observation, pattern, classroom mechanism, or next-step decision about - and model. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
Reason for review: Your team must decide what the evidence from - and model supports before submitting the labeled and result claim named on the lesson page.
Context: An works because an grabs only its matching , so a color signal is not random staining; it is proof that a specific target was present, which is what makes the test trustworthy.
- • T1: Draw an and its matching and label the specific binding site.
- • T2: Read how an uses that binding plus a color reaction to detect a target.
- • T3: Run the model with your dilution series, recording color at each well.
- • T4: Match each well's color to a concentration using your .
- • T5: Identify which model well represents a positive result and explain why.
- • T6: Write one sentence on how specificity makes the test trustworthy.
- • E1: Antibodies bind only to their specific at the binding site; this lock-and-key specificity prevents cross-reactions.
- • E2: An binds only its specific , so the color it produces reliably signals that exact target and how much of it was present, which is what makes the a trustworthy diagnostic.
- • E3: You will be able to explain - specific binding.
Measurements: Use only the measurements, units, graph, or counts supplied in today's task. No additional patient measurement is implied.
Figure finding: Teaching diagram for - and model. Trace the labeled testing, treatment, or biological process and identify where evidence limits the decision. This is a teaching model, not patient or experimental data.
Uncertainty: This is a composite classroom scenario. Missing history, measurements, or confirmation tests remain unknown and limit the conclusion.
For a linear , y = mx + b. To estimate an unknown concentration, use x = (y - b) / m.
A is y = 0.40x + 0.10. An unknown signal is 0.90. x = (0.90 - 0.10) / 0.40 = 2.0 concentration units.
Signal units belong on y. Concentration units belong on x. Confirm the unknown falls inside the standards before interpreting it.
Use the equation or graph supplied today to estimate one unknown. Show the substitution, concentration unit, and range check.
- • The solution must address the stated need in - and model.
- • The decision must be supported by E1-E3.
- • The final product must make the success criteria visible.
- • Complete the work inside the 80-minute block.
- • Use only supplied or teacher-approved materials and evidence.
- • Do not trade , accessibility, or privacy for speed.
- • and evidence quality: must pass before scoring other criteria.
- • User need and effectiveness: highest scored criterion.
- • Time, cost, and ease of use: compare only after and effectiveness pass.
Test evidence: For each option, record the E1-E3 result that supports or fails each criterion. Do not assign a score without a named observation.
- Version or option tested
- Criterion met or missed
- Evidence ID and result
- Revision made
- Reason for the revision
- Need and user
- Criteria and constraints
- Chosen option and evidence
- Test result
- Revision and reason
Students often think Students often assume any color in a well means the patient is positive, treating color itself as the answer regardless of how much or whether the actually bound its target.. The trap: Color only means a positive result if it comes from specific - binding above your background level, because a faint tint can also come from leftover reagent or a control well that should stay clear. The signal is trustworthy because the antibody binds only its target, so you compare each well to your and your curve, not to 'is there any color at all.'
Antibody specificity makes the test trustworthy because each antibody binds only its matching antigen, so a strong color signal means the specific target really is present, not some other molecule.
Positive result: Well 1 showed the strongest color and the highest concentration, so it is the positive result; the antigen was present at a high enough level to drive the enzyme color reaction.
| Well | Observed color | Concentration from curve |
|---|---|---|
| Well 1 | Dark blue | 100 ng/mL (positive) |
| Well 2 | Medium blue | 10 ng/mL |
| Well 3 | Light blue | 1 ng/mL |
| Well 4 | Nearly clear | ~0.1 ng/mL (negative) |
This model shows the level of evidence and organization needed to complete: A data table of model ELISA wells with observed color and the concentration assigned from the standard curve, identifying which well is a positive result and why.
- Name the variables and include units.
- Enter observations without changing the raw values.
- Check labels, calculations, and patterns before interpreting the data.
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: Bring to Friday's submission session; photograph for portfolio.
- 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 Antigen-antibody and ELISA model. 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.
Use this if you were absent, got stuck, or need another pass before you submit the lesson artifact.
Placement rationale
Matched model, dilution, by path:Medical-Interventions/Unit-1_How-to-Fight-Infection/1.1_The-Mystery-Infection; keywords:elisa, , dilution. Score 154. Visibility: student-schoology (student-facing resource; link through Schoology rather than local path).
Open this when the class reaches this activity and use it to complete the required lesson artifact.
Placement rationale
Matched model, dilution, by path:Medical-Interventions/Unit-1_How-to-Fight-Infection/1.1_The-Mystery-Infection; keywords:elisa, . Score 146. 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 model, dilution, by path:Medical-Interventions/Unit-1_How-to-Fight-Infection/1.1_The-Mystery-Infection; keywords:, dilution. Score 142. 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 - and model. It cannot by itself prove causation, establish a real clinical diagnosis, or justify action outside this classroom task.
In the ELISA model, more antigen bound produces a stronger color. Two wells develop color: one deep, one faint. Using your standard curve, which well came from the higher-concentration sample, and what does the color intensity physically represent?
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▸
I can name the procedure's purpose and the evidence I will record. I can identify each named hazard and the control that reduces it: Goggles and gloves required for the full model run even with food-coloring solutions. My data table is ready before materials are handled.
Finish the checklist before you handle any material.
- • Goggles and gloves required for the full model run even with food-coloring solutions.
- • Students must follow the labeled well layout exactly; switching wells invalidates the standard curve comparison.
- • Dispose of used pipette tips in the designated waste container, not loose in the trash.
- • Any spill on skin or eyes: rinse immediately with water; report to teacher.
- 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
- 2Draw an antigen and its matching antibody and label the specific binding site.
- 3Read how an ELISA uses that binding plus a color reaction to detect a target.
- 4Run the ELISA model with your dilution series, recording color at each well.
- 5Match each well's color to a concentration using your standard curve.
- 6Identify which model well represents a positive result and explain why.
- 7Write one sentence on how antibody specificity makes the test trustworthy.
- 8Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
- 9Complete the named cleanup and waste route, remove PPE safely, wash hands when required, and confirm the station is ready for the next group.
| Trial or sample ID | Independent condition | Measured result with units | Observation before interpretation | Quality-control note |
|---|---|---|---|---|
Before the procedure, predict the result and cite the rule behind the prediction.
After the procedure, compare the result with the prediction and name one limitation or source of uncertainty.
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.
If you are away, complete a virtual simulation and use the teacher color dataset to match wells to concentrations, then submit your interpretation.
learn.genetics (Utah) virtual labsThen submit your Data table. 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.
Class still runs. Complete the online activity above (it's self-guided). Need the concept taught without a teacher? Use this authoritative explainer:
HHMI BioInteractive (preview; use fallback if blocked)- 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.
- Error analysis and method · counts doubleName a specific limit of the method and how it moved your result, and compare what you predicted to what happened. "Human error" does not count; say what about the procedure or instrument caused it.