Gel map
Open your materials, follow the steps, then turn in your work.
Interpret your gel by estimating fragment sizes and confirming the plasmid identity.
1. Open your materials
Use the materials named in the first step below. Open lesson resources.
2. Start the work
Measure the migration distance of the DNA ladder bands.
Show all 5 required steps
- Measure the migration distance of the DNA ladder bands.
- Build a standard curve relating distance to fragment size.
- Estimate the size of each sample band from the curve.
- Compare estimated sizes to the expected restriction map.
- Conclude whether the plasmid matches the predicted construct.
Lost your place? If you stopped partway, check your data table: if the ladder distances are recorded, jump to 'build a standard curve relating distance to fragment size'; if not, start by measuring each ladder band's migration distance.
Check your work before submitting
- You estimated sample fragment sizes from a ladder.
- You concluded whether the gel matches the expected map.
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
- Gel analysis table with ladder band migration distances, standard curve (log fragment size vs. distance), estimated sample fragment sizes, predicted restriction map sizes, and a written conclusion on plasmid identity.
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 helpYou get two school days for every day you were absent, so this deadline moves with you.
How this lesson connects
Keep using what you learned last class: Transformation and gel electrophoresis are the foundational recombinant-DNA techniques because one inserts new DNA into cells and the other separates DNA by size, so together they let you build a construct and then verify it. Today: A gel map confirms a construct because a log-linear standard curve converts each band's migration distance into an estimated size, so matching those sizes to the predicted restriction map proves the plasmid is correct.
Optional: listen or watch a unit review▸
Need help? Warm-up, timing, and directions▸
💡 Big idea: A gel map confirms a construct because a log-linear converts each band's distance into an estimated size, so matching those sizes to the predicted restriction map proves the is correct.
- 0-5 minWarm-up: why does a smaller DNA fragment migrate farther in an gel?
- 5-20 minMeasure distances for every ladder band and record in a table
- 20-40 minBuild a (log fragment size vs. distance)
- 40-55 minInterpolate estimated sizes for all sample bands using the curve
- 55-70 minCompare estimates to the predicted restriction map; write your conclusion
- 70-80 minExit ticket: state whether your matches the expected construct and why
- • Yesterday you ran the gel. Today you extract the information from it.
- • The ladder is the key: each known band gives you one point on a .
- • Once you have the curve, you read off the size of every sample band.
- • If your sizes match the predicted restriction map, you've confirmed the .
- • distance is inversely related to fragment size on an gel.
- • A log-linear built from the ladder lets you interpolate unknown fragment sizes.
- • If estimated fragment sizes match the predicted restriction map, the identity is confirmed.
PLTW connection and today's work
Open Problem 6 in your myPLTW course shell and navigate to the gel analysis activity, then interpret your gel by estimating fragment sizes from the DNA ladder.
Today's stopping point: The wet lab data is collected; gel analysis is the interpretation milestone following the lab, so check your activity guide.
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
- Project 6.1.2 Construction and Cloning of Recombinant DNA
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
Finish the assigned lab safely before starting extra practice.
Lesson resources: reading, slides, 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.
and are the foundational recombinant-DNA techniques because one inserts new DNA into cells and the other separates DNA by size, so together they let you build a construct and then verify it.
A gel map confirms a construct because a log-linear converts each band's distance into an estimated size, so matching those sizes to the predicted restriction map proves the is correct.
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: Your ladder bands sit at known sizes. Using how far each one traveled, how do you estimate the size of your unknown sample bands, and how does matching them to the predicted restriction map confirm you have the right ?
What you already know: and are the foundational recombinant-DNA techniques because one inserts new DNA into cells and the other separates DNA by size, so together they let you build a construct and then verify it.
New idea: A gel map confirms a construct because a log-linear converts each band's distance into an estimated size, so matching those sizes to the predicted restriction map proves the is correct.
Visual or model: F1. F1. A lesson illustration or teaching diagram for Gel map. Use it with E1-E3; it is a model or context image, not experimental or patient data. What to notice: Trace the labeled system, test, or design relationship and identify which evidence should trigger revision.
- Observe or measure the relevant feature in gel map.
- 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: Your ladder bands sit at known sizes. Using how far each one traveled, how do you estimate the size of your unknown sample bands, and how does matching them to the predicted restriction map confirm you have the right ?
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.
- • : The process by which a bacterial cell takes up foreign DNA, such as a , from its surroundings and begins using those new genes.
- • selection: The process of choosing among options using set criteria, such as picking the best design solution or the strongest candidate.
- • : A visible cluster of identical microorganisms growing on a plate, all descended from a single original cell.
- • digest: To cut DNA at specific sequences using restriction enzymes, producing defined fragments that scientists can sort, study, or join together.
- • : A lab method that uses an electric field to pull DNA fragments through a gel so they separate by size and show up as bands.
- • : A set of DNA fragments of known sizes run alongside samples in to measure the length of unknown bands.
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.
Molecular workflows use controls and complementary separation or detection steps to evaluate a target, while each band, fraction, or remains limited by method resolution and sample quality.
Limit: A band, selected , or fluorescent fraction alone does not prove identity, , correct sequence, biological activity, or clinical suitability.
Stored information can be copied, read, and converted into a functional product.
Limit: Genes are regulated biological sequences, not conscious instructions, and one gene rarely determines a whole trait alone.
You estimated sample fragment sizes from a ladder.
Limit: E3 defines the classroom product or success criterion. It is not independent scientific evidence and cannot justify a clinical or causal claim.
PLTW-BFH-2027-05-07 · Simulated classroom evidence scenario
Your role: biomedical design team member
Decision: Your team must decide what the evidence from gel map supports before submitting the labeled and result claim named on today's page.
- • Bands outside the ladder's range cannot be sized from this curve, so run a wider ladder first.
- • Plot ladder distance against the log of size, then read your unknown bands off that .
- • Estimate that a band traveling twice as far as another is exactly half its size in .
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: Today's evidence supports a classroom claim about gel map. It cannot prove causation, diagnose a real patient, or justify action outside this room.
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.
Students often think Students think distance and size scale in a straight line, so a band that traveled twice as far must be exactly half the size.. The trap: is not linear with size; it is roughly linear with the LOG of size. That is why you plot distance against log(size) to build the , because using plain size would badly misread every band that is not near a ladder rung.
Step 1, ladder distances (mm migrated from well):
- 1000 bp band: 14 mm
- 700 bp band: 19 mm
- 500 bp band: 24 mm
- 300 bp band: 31 mm
Step 2, standard curve: I plotted log(fragment size) on the y-axis against migration distance on the x-axis; the points fall on a near-straight line, so I can read sizes between the markers.
Step 3, sample band estimates from the curve:
- Sample band at 22 mm is about 600 bp.
- Sample band at 28 mm is about 380 bp.
Step 4, compare to the predicted restriction map: My map predicted a double digest would give fragments of about 600 bp and 400 bp.
Conclusion: My estimated sizes (about 600 bp and 380 bp) are close to the predicted 600 bp and 400 bp, so the gel is consistent with the expected construct and the plasmid identity is confirmed within the limits of gel estimation.
| Ladder band (bp) | Distance (mm) |
|---|---|
| 1000 | 14 |
| 700 | 19 |
| 500 | 24 |
| 300 | 31 |
This model shows the level of evidence and organization needed to complete: Completes the gel-map step: ladder band migration distances, a standard curve relating distance to fragment size, estimated sample fragment sizes, the predicted restriction-map sizes, and a conclusion on plasmid identity.
- 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: Submit your gel map data table and conclusion on Schoology today.
- 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 Gel map. 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 , , molecular evidence by path:Biomedical-Innovations/Problem-6_Molecular-Biology/6.1_Molecular-Biology; keywords:transformation, , molecular. 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 , , molecular evidence by path:Biomedical-Innovations/Problem-6_Molecular-Biology/6.1_Molecular-Biology; keywords:gel, molecular. 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 , , molecular evidence by path:Biomedical-Innovations/Problem-6_Molecular-Biology/6.1_Molecular-Biology; keywords:transformation, molecular. 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 gel map. It cannot prove causation, diagnose a real patient, or justify action outside this room.
Your standard curve gives a sample band a size of about 1050 bp, and the restriction map predicts a 1000 bp fragment. Does this confirm the plasmid or not? Explain.
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.
Missed class or ready for more?▸
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.
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.
- • 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.
- 1Before materials are handled, identify the purpose, variables or comparison, controls, measurement units, and stop-work condition.
- 2Measure the migration distance of the DNA ladder bands.
- 3Build a standard curve relating distance to fragment size.
- 4Estimate the size of each sample band from the curve.
- 5Compare estimated sizes to the expected restriction map.
- 6Conclude whether the plasmid matches the predicted construct.
- 7Record each result in the prepared table before interpreting it. Mark missing, repeated, or invalid results truthfully.
- 8Complete 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.
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 Data table 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:
Learn.Genetics (University of Utah): gel electrophoresisYou've passed Unit 2, so the optional extra-credit track is open. Complete reserved-unit work from home, including virtual labs, for extra credit. Each item shows its correct submission route.
Open the extra-credit track- 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.
- SubmittedGo 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 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.
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