Dilution and ELISA model submission

Open your materials, follow the steps, then turn in your work.

Submit your standard curve, model ELISA data, and interpretation to close the dilution week.

Before lab work: Read the safety rules below and wait for your teacher’s approval. You may read the directions while you wait.

1. Open your materials

Use the materials named in the first step below. Open lesson resources.

2. Start the work

Finalize your standard-curve graph and label the axes clearly.

Show all 6 required steps
  1. Finalize your standard-curve graph and label the axes clearly.
  2. Tabulate your model ELISA colors and the concentration you assigned each well.
  3. Write a short interpretation naming which samples were positive and how you knew.
  4. Add one sentence on a source of error in reading colors by eye.
  5. Submit your graph, data table, and interpretation on the class site.
  6. Confirm it is turned in and note one thing you want to do more carefully in the wet lab.

Lost your place? Lost your place? Check what is finished: standard-curve graph with labeled axes, then the data table of well colors and assigned concentrations, then your written interpretation. Whatever is missing, do it next, then submit all three on the class site and confirm it turned in.

Check your work before submitting

  • You will be able to submit a labeled standard curve and ELISA data.
  • You will be able to interpret model results against a curve.
  • You will be able to name a source of measurement error.

Before lab work: read the safety rules

  • Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start.
  • Human samples and data stay private: label with a code, never a name, and dispose of materials in the correct waste container, then wash your hands.

3. Turn in your work

DueCheck Schoology
Hand in
Standard curve graph, model ELISA data table (colors and concentrations), short interpretation of positive results, and one error sentence.
How to submit and name your file

Use the submission route shown on today's today's page.

In Schoology, open your course and the assignment for this lesson. Attach your file, select Submit, and check that it appears in the submission.

PDF upload help

You get two school days for every day you were absent, so this deadline moves with you.

Find this lesson's Schoology assignments

These are existing assignments for your section. Follow the directions in the assignment you are working on; this list does not add new work. Check Schoology for each deadline.

Link will not open? Open Schoology, choose your course and section, and find the title shown above.

How this lesson connects

Keep using what you learned last class: Keep supplied details separate from conclusions. An illustrative color pattern can help explain a model, but it cannot establish a test result without the required reference information and decision rule. Today: A result travels with its graph, data, and interpretation and openly names its error, so that another scientist can replicate it and know exactly how far to trust it.

Optional: listen or watch a unit review
Optional unit study notebook
Serial dilution, antibodies, and the ELISA test for detecting a target in a sample.
Open the notebook
Optional review video
Audio overviewVideo overviewMind mapStudy guideFlashcardsQuizData table
Thinking practice for this week
CER · ArgumentThinking like a scientist · Part 4 of 4

Argument: disagreeing well, and when opinion becomes fact

How do we argue productively when we disagree, and when does a claim become accepted as fact?

An argument is not a fight. It is two or more people testing claims against evidence to get closer to the truth. The best disagreements aim at the strongest version of the other side (steelman it), refute the actual reasoning, and stay about the idea, not the person.

A sound argument and a clash of opinions are different things. Opinions can simply differ and both stand. A scientific argument is settled by evidence: the side with stronger, more reliable evidence and better reasoning should win, and everyone should be willing to update.

So when does an opinion become a fact? In science, a claim becomes accepted not because enough people like it, but when independent evidence keeps supporting it and repeated attempts to disprove it fail. That is consensus, and it is provisional: it holds until better evidence changes it. Truth is not a vote, but agreement among many careful, independent investigations is the best signal we have.

A good argument
  • Steelmans: it takes on the strongest version of the other side.
  • Targets reasoning and evidence, never the person.
  • Is settled by evidence, not by who is louder or more popular.
  • Stays open: the participants will change their minds if the evidence does.
Opinion vs. established fact
  • A claim earns the label “fact” through repeated, independent evidence, not a popularity vote.
  • Even strong consensus stays open to revision if better evidence appears.
Do this today

Take a claim from this course that people might dispute. Write the strongest argument for it and the strongest against it, then say which the evidence supports and what would change your mind.

Need help? Warm-up, timing, and directions

💡 Big idea: A result travels with its graph, data, and interpretation and openly names its error, so that another scientist can replicate it and know exactly how far to trust it.

  1. 0-15 minFinalize the standard-curve graph: check axis labels, units, and best-fit line
  2. 15-30 minComplete the : well ID, observed color, assigned concentration for every well
  3. 30-50 minWrite the interpretation paragraph: name positive results and explain the evidence from the curve
  4. 50-62 minWrite the error sentence: name one specific source of uncertainty in reading colors by eye
  5. 62-72 minSubmit graph, , and interpretation to the class site
  6. 72-80 minConfirm all items show as turned in; note one thing to do more carefully in the wet lab next week
Mr. Mendoza's 5-minute intro
  • The goal of any lab exercise is not just to run the procedure; it is to produce a record someone else can evaluate.
  • Today you finalize and submit everything from the dilution week: the , the data, and the interpretation.
  • Next week you run the real wet ; what you notice about your errors today shapes how carefully you work then.
  • Exit goal: all three submission items confirmed as turned in before you leave.
Know by the end
  • A complete submission packages the visual evidence (graph), the raw data (table), and the interpretation together.
  • Naming a source of error is part of good science; it shows you understand the limits of your own data.
  • Reviewing your model data before the wet helps you anticipate where precision matters most.

PLTW connection and today's work

Open the ELISA pre-lab submission in myPLTW for Activity 1.1.5 ELISA and confirm your standard-curve work is ready for next week's wet lab.

Today's stopping point: Standard-curve table should be done (Thursday); full pre-lab packet submitted today.

PLTW activity titles identify the course connection. If your account will not open, use the posted materials for today and tell Mr. Mendoza. Do not mark an online activity complete unless you completed it.

Course connection

  • Activity 1.1.5 ELISA
Open Activity 1.1.5 ELISA in myPLTW

Use the turn-in directions at the top of this page. Do not create a second submission unless your teacher asks for one.

Show another explanation or a smaller first step

Need help? Choose a starting point

Run the lab
Finalize and submit all three parts: the labeled standard-curve graph, the data table of colors and concentrations, and a short interpretation naming which samples were positive and how you knew, plus one honest source of error.
Missed class? Start here
Absent or catching up: assemble your three parts from your notes and the model data, write two sentences of interpretation (which well was positive, why), and submit on the class site. Add the error sentence if you have time.

Finish the assigned lab safely before starting extra practice.

Lesson resources: reading, slides, and vocabulary
Socratic teaching slide deck

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.

Carry forward

Keep supplied details separate from conclusions. An illustrative color pattern can help explain a model, but it cannot establish a test result without the required reference information and decision rule.

Daily take-home

A result travels with its graph, data, and interpretation and openly names its error, so that another scientist can replicate it and know exactly how far to trust it.

Inspect the analogy

A research team lays out its question, variables, controls, sampling plan, measurement record, and analysis before deciding what the data support.

  1. Which variable is changed or compared?
  2. Which conditions and measurements must stay consistent?
  3. Which conclusion is inside the study's evidence boundary?
Rule

Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.

Where it breaks

A well-organized classroom study can still be limited by , measurement quality, confounding, and the population represented.

Map the analogy to biology
  • Question and variable cards map to the study design.
  • Control and measurement cards map to fair, reproducible data collection.
  • The conclusion card maps to a bounded claim supported by the analysis.
Read this first

Driving question: You know which model wells were positive, but a reviewer who was not in the room does not. How do you package your , your data, and your reasoning so they could replicate and trust your call?

What you already know: Keep supplied details separate from conclusions. An illustrative color pattern can help explain a model, but it cannot establish a test result without the required reference information and decision rule.

New idea: A result travels with its graph, data, and interpretation and openly names its error, so that another scientist can replicate it and know exactly how far to trust it.

Visual or model: F1. F1. A lesson illustration or teaching diagram for Dilution and ELISA model submission. 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.

  1. Observe or measure the relevant feature in today's lesson.
  2. Organize the observation with a stable evidence ID.
  3. Apply this rule: Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.
  4. Choose the option the evidence supports and state the limit of the conclusion.

Real biomedical example: You know which model wells were positive, but a reviewer who was not in the room does not. How do you package your , your data, and your reasoning so they could replicate and trust your call?

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.

Vocabulary:
  • : 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 immune with two -binding tips that marks a specific foreign target for destruction or neutralization.
  • : A lab test that uses antibodies linked to a color-producing to detect and measure a specific in a sample.
  • : 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.

Evidence set and decision
E1 · Source fact

An uses selective binding and controls to produce a measurable signal, but performance, cross-reactivity, sampling, and the decision threshold limit what a result can establish.

Limit: A classroom result does not establish a clinical diagnosis or an exact target concentration unless the validated and support that use.

E2 · Teaching model

Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.

Limit: A well-organized classroom study can still be limited by , measurement quality, confounding, and the population represented.

E3 · Task criterion

You can submit a labeled and data.

Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.

PLTW-GEND-2026-09-21 · Simulated classroom evidence scenario

Your role: medical interventions team member

Decision: Your team must decide what the evidence from today's lesson supports before submitting the lab report named on today's page.

  • Wait on a recommendation until the clinic reports how often this test misses sick people and flags healthy ones.
  • Decide whether to use the test by asking which error, or , this clinic can afford.
  • Reject the test until the lab fixes its mistakes, because an accurate test should not give false results.

Response: State one choice, cite at least two evidence IDs, explain the rule that connects them, and add one limitation. Submit it as the lab report.

Claim ceiling: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.

Composite case file · PLTW-GEND-2026-09-21

Reason for review: Your team must decide what the evidence from today's lesson supports before submitting the lab report named on today's page.

Context: A result is only as trustworthy as its documentation: the graph, the raw data, and the interpretation have to travel together, and naming your own sources of error is what turns a claim into evidence someone else can check.

Timeline:
  • T1: Finalize your standard-curve graph and label the axes clearly.
  • T2: Tabulate your model colors and the concentration you assigned each well.
  • T3: Write a short interpretation naming which samples were positive and how you knew.
  • T4: Add one sentence on a source of error in reading colors by eye.
  • T5: Submit your graph, , and interpretation on the class site.
  • T6: Confirm it is turned in and note one thing you want to do more carefully in the wet lab.
Evidence records:
  • E1: An uses selective binding and controls to produce a measurable signal, but performance, cross-reactivity, sampling, and the decision threshold limit what a result can establish.
  • E2: Define variables, controls, sampling, units, and the analysis plan before interpreting a result; analysis cannot repair biased or inconsistent measurement.
  • E3: You can submit a labeled and data.

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 Dilution and model submission. 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.

Math moment
Formula or setup

For a linear , y = mx + b. To estimate an unknown concentration, use x = (y - b) / m.

Worked parallel example

A is y = 0.40x + 0.10. An unknown signal is 0.90. x = (0.90 - 0.10) / 0.40 = 2.0 concentration units.

Units and reasonableness

Signal units belong on y. Concentration units belong on x. Confirm the unknown falls inside the standards before interpreting it.

Try it with today's data

Use the equation or graph supplied today to estimate one unknown. Show the substitution, concentration unit, and range check.

Watch the trap

Students often think Students often think admitting a source of error weakens their result, so they leave it out to look more confident.. The trap: Naming a source of error strengthens a result, because it shows you know the limits of your data and where a reader should be cautious. A result with no stated limits looks less trustworthy to a scientist, not more, because every real measurement has error, and hiding it just makes the reader find it for you.

Worked example · a parallel case (guides, does not reveal)
Dilution and ELISA model report
Completes: A packaged submission with the labeled standard curve, the model ELISA data table, a short interpretation of which samples were positive, and one source of error.

Interpretation: Well 1 was positive because its color matched the most concentrated standard on my curve, while Well 4 was effectively negative. I knew this by reading each well's color signal across to the best-fit line and down to its concentration.

Source of error: reading colors by eye is subjective, so two people might assign slightly different concentrations to a medium-blue well; a plate reader would reduce this error.

For the wet lab I want to: pipette more carefully so my dilution steps are exactly tenfold.

Why this matters

This model shows the level of evidence and organization needed to complete: A packaged submission with the labeled standard curve, the model ELISA data table, a short interpretation of which samples were positive, and one source of error.

Build yours step by step
  1. State the question and method.
  2. Present the observations and data with units.
  3. Explain the result, limitations, and next investigation.
Change it for a new task

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 graph, data table, and interpretation on Schoology.

See the full worked example
Portal terms
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.
This unit's vocabulary
/AN-tih-jen//AN-tih-bod-ee/(Enzyme-Linked Immunosorbent Assay)/ee-LY-zuh/

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.

Build your vocabulary · optional, for extra credit

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 Dilution and ELISA model submission. 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.

antigen
antibody
ELISA
serial dilution
standard curve
substrate

Saved on this device. Show Mr. Mendoza or add these to your notebook glossary to claim the extra credit.

Teacher-posted resources

Classroom documents for this lesson are posted in Schoology. Open Clever, then Schoology, and find each one by the name shown on its card.

Catch-up / reteachFor: Need extra support
MI 1.1.5 Serial Dilutions student resource sheet
worksheet/handoutPosted in Schoology
Open in Schoology

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).

Use during lessonFor: Everyone
Activity 1.1.5 ELISA (full activity)
worksheet/handoutPosted in Schoology
Open in Schoology

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).

Catch-up / reteachFor: Need extra support
MI 1.1.5 Student Resource Sheet Serial Dilutions
worksheet/handoutPosted in Schoology
Open in Schoology

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).

Sign in to Clever with your district Microsoft account to open Schoology or myPLTW. Follow today's posted steps. If myPLTW will not open, use the posted alternative and tell Mr. Mendoza. Turn in your completed work through the Schoology assignment.

Practice: try a question, then check your answer

Claim ceiling for this check: Today's evidence supports a classroom claim about today's lesson. It cannot prove causation, diagnose a real patient, or justify action outside this room.

Quick self-check · commit, then reveal

A classmate submits an ELISA lab report with a beautiful graph and a data table, but no sentence about sources of error and no written interpretation of which samples were positive. Name two things a reviewer could NOT do with this submission, and why.

How sure are you?

Write an answer and pick a confidence to unlock the key.

Cumulative WebXam review · flash practice

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.

Tap an answer to check it · nothing is recorded or graded
[Review: Lab Safety & the Safety Data Sheet (SDS)] What does the abbreviation GLP stand for in a regulated biomedical laboratory?
[Review: Framing an Outbreak Investigation] Which microbiology principle states that one specific organism causes a specific disease and can be isolated from a host who has that disease?
[Review: Who is the culprit? Identifying a pathogen with DNA and BLAST] What was the landmark international collaboration that identified the nucleotide base pairs of humans?
An antigen is best described as which of the following?
Missed class or ready for more?
🔬 Pre-lab simulation

Run this before you touch the bench. It is built from the real lab procedure, so the decisions you make here are the ones you will make with the equipment in your hands.

The Ruler You Make Yourself
Open the simulation →
Lab · prepare, conduct, complete
1Prepare
Pre-lab pass · clear all six to go to the bench
0/6

I can name the procedure's purpose and the evidence I will record. I can state today's specific hazards and the control for each. If this deck does not name them, I ask Mr. Mendoza before I touch anything. My data table is ready before materials are handled.

Finish the checklist before you handle any material.

Bring / set up
Micropipettes and tipsMicrocentrifuge tubes or microplateStock antigen solutionBuffer or diluentMicroplate or tube rackLab notebook for the dilution table
Safety · specific to today's hazards
  • Wear the required PPE, keep the bench clear, handle equipment only as directed, and know where the eyewash, sink, and spill kit are before you start.
  • Human samples and data stay private: label with a code, never a name, and dispose of materials in the correct waste container, then wash your hands.
Review Lab Safety (rules, PPE, SDS, emergencies) and check your contract + test
2Conduct (Argument-Driven Inquiry)
  1. 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
  2. 2Finalize your standard-curve graph and label the axes clearly.
  3. 3Tabulate your model ELISA colors and the concentration you assigned each well.
  4. 4Write a short interpretation naming which samples were positive and how you knew.
  5. 5Add one sentence on a source of error in reading colors by eye.
  6. 6Submit your graph, data table, and interpretation on the class site.
  7. 7Confirm it is turned in and note one thing you want to do more carefully in the wet lab.
  8. 8Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
  9. 9Complete the named cleanup and waste route, remove PPE safely, wash hands when required, and confirm the station is ready for the next group.
Prepare this data table before materials are handled
Trial or sample IDIndependent conditionMeasured result with unitsObservation before interpretationQuality-control note
     
     
     
HHMI BioInteractive (preview; use fallback if blocked)
3Complete
Argue from your evidence, then compare what you predicted to what happened. Error analysis names a specific method limit, never "human error".
You predicted

Before the procedure, predict the result and cite the rule behind the prediction.

What actually happened

After the procedure, compare the result with the prediction and name one limitation or source of uncertainty.

Your lab report is graded on the rubric below, with extra weight on error analysis and method.
Where this leads: careers

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.

What to do if you were absent
This one used the bench

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 Lab report with invented numbers.

If MR. MENDOZA is absent

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)
How this is graded
For: Lab report: Standard curve graph, model ELISA data table (colors and concentrations), short interpretation of positive results, and one error sentence.
  • Complete
    Every required part of the artifact is present, nothing left blank.
  • Accurate
    The science and the data are correct and match the evidence.
  • Scientific reasoning
    You explain your claim with evidence and reasoning (CER), not just an answer.
  • Professional communication
    Clear, organized, labeled, and written the way a clinician or scientist would.
  • Submitted
    Go to Schoology to turn this in. Submit one PDF. Put your first and last name in the document header. Name the file: FirstName LastName - Assignment Title - YYYY-MM-DD.pdf. If you cannot get in, see Mr. Mendoza. Do not skip the work.
  • Error analysis and method · counts double
    Name 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.