Question

Arrange the following steps in DNA fingerprinting using restriction fragment length polymorphism (RFLP) in the correct sequence
A. Electrophoresis is done
B. Scientists break the DNA into pieces using enzyme and cut segments of DNA are separated
C. Detected by fluorescent tag on their primer
D. Region of DNA containing STR is amplified by PCR using primer complementary to the non-repeating sequence flanking the repeats
E. Tandemly repeated DNA sequences occur in the genome, including short tandem repeats (STRs)
Choose the correct answer from the options given below:

• A. A, B, C, D, E
• B. E, B, D, A, C
• C. C, A, D, B, E
• D. B, E, C, A, D

Hint:

DNA Fingerprinting Steps: Identify repeat loci (E) $\rightarrow$ Enzymatic digestion (B) $\rightarrow$ Target PCR amplification (D) $\rightarrow$ Gel Electrophoresis (A) $\rightarrow$ Fluorescent/Probe Detection (C).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
DNA profiling and forensic polymorphic repeat marker analysis methodology sequence.

Step 2: Detailed Explanation:
Standard methodological progression in genomic DNA profiling:
1. Step 1 (E): Identification that tandemly repeated polymorphic DNA sequences (VNTRs/STRs) occur naturally throughout the genome.
2. Step 2 (B): Genomic DNA extraction and restriction endonuclease digestion into fragments.
3. Step 3 (D): Target polymorphic repeat regions are amplified via PCR using specific flanking primers.
4. Step 4 (A): High-resolution agarose or capillary gel electrophoresis separates DNA fragments by molecular size.
5. Step 5 (C): Band visualization and detection via fluorescent tags or radioactive probes.
Sequence: E $\rightarrow$ B $\rightarrow$ D $\rightarrow$ A $\rightarrow$ C.

Step 3: Final Answer:
Thus, the correct sequence is E, B, D, A, C, corresponding to option (B).