Monoclonal Antibodies & Pregnancy

Q: Which two cell types are fused together to produce a hybridoma cell capable of manufacturing monoclonal antibodies?

Correct Answer: A) B-Lymphocyte and Myeloma tumour cell. Explanation: B-lymphocytes produce specific antibodies, while myeloma tumour cells divide indefinitely. Mark Scheme: 1 mark for B-Lymphocyte and Myeloma (tumour) cell.

Q: Which hormone produced in early pregnancy is detected by home lateral flow test strips?

Correct Answer: A) hCG. Explanation: Human chorionic gonadotropin (hCG) is produced by the developing placenta and excreted in maternal urine. Mark Scheme: 1 mark for hCG.

Q: What is the primary diagnostic purpose of the 'control line' on a lateral flow antibody strip?

Correct Answer: A) To verify that the fluid has migrated properly across the entire test strip. Explanation: The control line binds excess mobile antibodies, confirming that the sample moved along the test strip successfully. Mark Scheme: 1 mark for verifying liquid migration / test validity.

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Key Learning Objectives

Explain how monoclonal antibodies are produced by fusing mouse lymphocytes with tumour cells to create hybridomas.
Detail the 3-zone lateral flow mechanism in pregnancy test strips (sample pad, mobile antibody zone, immobilised test/control zones).
Evaluate clinical applications of monoclonal antibodies in targeted cancer chemotherapy and medical diagnostics.

Topic Summary & Core Notes

Deconstruct how monoclonal antibodies are produced via hybridoma cells and how lateral flow test strips function using mobile and immobilised antibodies targeting hCG hormones.

Key Rules, Formulas & Definitions

Hybridoma Production

B-Lymphocyte (makes specific antibody) + Myeloma Tumour Cell (divides indefinitely) → Hybridoma Cell

Test Strip Zones

Reaction Zone (Mobile + Blue Dye) → Test Zone (Immobilised Anti-hCG) → Control Zone (Immobilised Anti-Mouse Ab)

2 Step-by-Step Worked Examples

Worked Example 1

Worked Example 1: Pregnancy Test Lateral Flow Mechanism

Question: Explain why a positive pregnancy test produces two blue lines, while a negative test produces only one line.

Step-by-Step Solution:

Step 1: Reaction zone: Urine contains hCG hormone in pregnant individuals, which binds to mobile blue dye-labelled antibodies.
Step 2: Test zone: hCG-antibody complexes are trapped by fixed immobilised antibodies, concentrating blue beads (Line 1).
Step 3: Control zone: Excess unbound antibodies continue along strip and bind to a second set of immobilised antibodies, proving the test worked (Line 2).

Final Answer: Positive: hCG binds mobile antibodies, trapped at test zone (line 1); excess continues to control zone (line 2). Negative: no hCG, mobile antibodies bypass test zone and only bind at control line.

Senior Examiner Insight: Always state that the control line proves the urine flowed properly across the strip.

Worked Example 2

Worked Example 2: Advantages in Cancer Therapy

Question: Describe how monoclonal antibodies can be engineered to treat cancer without damaging healthy tissue.

Step-by-Step Solution:

Step 1: Specificity: Cancer cells carry unique tumour antigens on their cell membranes.
Step 2: Conjugation: Toxic radioactive drugs or chemotherapy agents are chemically attached to monoclonal antibodies.
Step 3: Targeted delivery: Antibodies bind specifically to tumour markers, delivering cytotoxins exclusively to malignant cells.

Final Answer: Monoclonal antibodies bind specifically to cancer cell tumour antigens, delivering attached drugs directly to malignant cells without harming healthy tissue.

Senior Examiner Insight: Emphasise the word 'specific' binding to tumour antigens.

Common Pitfalls & Examiner Warnings

Common Mistake: Forgetting the function of the control line

The control line does NOT test for pregnancy; it confirms the liquid flowed correctly across the test strip.

Interactive Self-Check Quiz (3 Questions)

Question 1 of 3

Which two cell types are fused together to produce a hybridoma cell capable of manufacturing monoclonal antibodies?

A) B-Lymphocyte and Myeloma tumour cell

B) Phagocyte and Red blood cell

C) T-Lymphocyte and Stem cell

D) Platelet and Bacterial cell

Click to Reveal Answer & Mark Scheme

Correct Answer: A) B-Lymphocyte and Myeloma tumour cell

Detailed Explanation: B-lymphocytes produce specific antibodies, while myeloma tumour cells divide indefinitely.

Mark Scheme & Scoring Points: 1 mark for B-Lymphocyte and Myeloma (tumour) cell.

Question 2 of 3

Which hormone produced in early pregnancy is detected by home lateral flow test strips?

A) hCG

B) Oestrogen

C) Progesterone

D) LH

Click to Reveal Answer & Mark Scheme

Correct Answer: A) hCG

Detailed Explanation: Human chorionic gonadotropin (hCG) is produced by the developing placenta and excreted in maternal urine.

Mark Scheme & Scoring Points: 1 mark for hCG.

Question 3 of 3

What is the primary diagnostic purpose of the 'control line' on a lateral flow antibody strip?

A) To verify that the fluid has migrated properly across the entire test strip

B) To measure the precise concentration of the target hormone

C) To neutralise excess acidic urine

D) To sterilise the reactive chemicals

Click to Reveal Answer & Mark Scheme

Correct Answer: A) To verify that the fluid has migrated properly across the entire test strip

Detailed Explanation: The control line binds excess mobile antibodies, confirming that the sample moved along the test strip successfully.

Mark Scheme & Scoring Points: 1 mark for verifying liquid migration / test validity.

Created by Fiaraz Iqbal

Former Headteacher & Senior Science / Maths Examiner

Fiaraz produces structured video walkthroughs, Tier 3 literacy packs, and exam mark scheme breakdowns to help secondary students achieve top grades.

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