card 2 INDIRECT ELISA

4. In direct ELISA, the serum is first added to the:

A. Ribosome

B. Plate

C. PCR tube

D. Gel

Correct Answer: B. Plate

🧠 Explanation: Serum-ka ayaa plate-ka lagu daraa, antigen-kuna wuxuu ku coats/secure-gareeyaa surface-ka plate-ka.

5. In direct ELISA, the antibody that binds the antigen is:

A. Enzyme-labeled

B. Not labeled

C. A secondary antibody

D. A DNA probe

Correct Answer: A. Enzyme-labeled

🧠 Explanation: Direct ELISA → specific antibody ayaa enzyme lagu xiraa, kadibna wuxuu si toos ah ugu xirmaa antigen-ka.

6. What happens after the enzyme-labeled antibody binds in direct ELISA?

A. DNA is amplified

B. Substrate is added → color change

C. RNA is transcribed

D. Antibody is removed

Correct Answer: B. Substrate is added → color change

🧠 Explanation: Enzyme-labeled antibody → substrate → color change.

7. In indirect ELISA, the primary antibody is:

A. Enzyme-linked

B. Not enzyme-linked

C. Replaced by a DNA probe

D. Always a secondary antibody

Correct Answer: B. Not enzyme-linked

🧠 Explanation: Indirect ELISA → primary/specific antibody enzyme kuma xirna. Secondary antibody ayaa enzyme-linked ah.

8. In indirect ELISA, which antibody is enzyme-linked?

A. Primary antibody

B. Secondary antibody

C. Antigen

D. Capture antibody

Correct Answer: B. Secondary antibody

🧠 Explanation: Secondary antibody-ga ayaa enzyme-linked ah, wuxuuna ku xirmaa primary antibody-ga.

9. Which statement correctly compares direct and indirect ELISA?

A. Direct uses a secondary enzyme-linked antibody

B. Indirect uses an enzyme-linked primary antibody

C. Direct uses an enzyme-linked specific antibody; indirect uses an enzyme-linked secondary antibody

D. Both use only DNA probes

Correct Answer: C. Direct uses an enzyme-linked specific antibody; indirect uses an enzyme-linked secondary antibody

🧠 Explanation: Direct → primary/specific antibody enzyme-linked. Indirect → secondary antibody enzyme-linked.

10. A major advantage of indirect ELISA is that the:

A. Specific antibody does not need to be enzyme-linked

B. Antigen does not bind the plate

C. DNA is amplified

D. Secondary antibody is unnecessary

Correct Answer: A. Specific antibody does not need to be enzyme-linked

🧠 Explanation: Indirect ELISA waxay fududayn kartaa helitaanka specific antibody, sababtoo ah specific antibody-ga enzyme looma baahna inuu ku xiran yahay.