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Question #45173
The Question
A biotechnology company manufactures an ELISA kit for detecting a novel viral infection by utilizing recombinant antibodies produced in E. coli. Recently, a severe quality control breach occurred due to bypassed GEAC (Genetic Engineering Appraisal Committee) oversight, resulting in widespread false-negative reports in infected patients. Which of the following best explains the molecular basis of these false-negative results?
Options
- A.
The unapproved recombinant vectors underwent a mutation that altered the paratope structure of the synthesized antibodies, resulting in a loss of specific binding affinity for the viral antigen.
- B.
The lack of GEAC regulation led to the use of wild-type E. coli that secreted endogenous peroxidases, causing premature cleavage of the chromogenic substrate.
- C.
The recombinant antibodies exhibited high cross-reactivity with normal human serum proteins, competitively excluding the viral antigens from binding.
- D.
The bypassed oversight allowed the use of vectors lacking a selectable marker, causing the ELISA plates to reject the adsorption of the antigen-antibody complexes.
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Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
GEAC Oversight|Alien Species Invasion Impacts|Biotic Interactions
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students must distinguish between molecular errors that cause false positives versus false negatives.
While cross-reactivity or background enzyme activity (Options B and C) lead to false positives, a structural mutation in the capture reagent leads to a failure in antigen binding, causing a false negative.
Furthermore, it tests the integration of NCERT concepts from Biotechnology Principles (selectable markers) and Applications (ELISA, GEAC).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Biotechnology and Its Applications - Class 12 |
| Concept | GEAC Oversight |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |