A. Peak identification
B. Comparison to allelic ladder
C. Genotype assignment to alleles
D. Color separation
E. Peak sizing
Choose the correct answer from the options given below:
STR Process: Color Separation
The process begins with Color Separation (D). In STR analysis, different fluorescent dyes are attached to primers for various STR loci or alleles. This allows the detection system to distinguish between different DNA fragments based on their color during electrophoresis.
STR Process: Peak Identification
Following color separation, Peak Identification (A) occurs. Analytical software examines the electropherogram generated during electrophoresis. It detects and flags signals that rise above the background noise, indicating the presence of potential DNA fragments.
STR Process: Peak Sizing
Next is Peak Sizing (E). Once potential peaks are identified, the software calculates their precise size, typically measured in base pairs (bp). This is achieved by comparing the migration distance of the sample peaks to that of a size standard run concurrently.
STR Process: Comparison to Allelic Ladder
The sized peaks are then subjected to Comparison to Allelic Ladder (B). An allelic ladder, containing known common alleles for the STR loci being tested, is run alongside the sample. The sizes of the sample peaks are meticulously compared to the sizes of the known alleles in the ladder.
STR Process: Genotype Assignment
The final step is Genotype Assignment (C). Based on the comparison with the allelic ladder, specific allele designations (e.g., '10', '11.2') are assigned to each STR locus. The combination of alleles at each locus defines the individual's STR profile or genotype.
Correct Order Summary
Therefore, the correct sequence of steps involved in STR profile determination is: Color separation (D) → Peak identification (A) → Peak sizing (E) → Comparison to allelic ladder (B) → Genotype assignment (C).
Important Questions from Molecular Biology Techniques
Which one of the following does NOT use RNA-sequencing?
Which one of the following statements related to molecular cloning procedures is INCORRECT?
Amongst the following, which one is the most appropriate strategy to sequence and assemble highly repeated regions of a genome?
Given below are statements related to various molecular techniques
A. During molecular cloning of DNA fragments, a vector and insert molecule digested with two different enzymes can never be ligated with each other.
B. Only 3' → 5' exonucleases and not 5' → 3' exonucleases can be used for digesting nucleic acids to generate blunt-ended fragments for cloning.
C. In Sanger's dideoxy sequencing method, each reaction consists of a mixture of three dNTPs and one ddNTP.
D. Self-ligation of a vector with compatible ends can be prevented by treatment with alkaline phosphatase.
Which one of the following options represents a combination of correct statements?
Given below are four DNA sequences and a set of forward and reverse primers for PCR amplification.
In the absence of any other factors such as (but not restricted to) Tm, length, percent GC, etc., which one of the above template-primers combinations would produce an amplified fragment?Sequence Primes A 5' ACAATCGT.....ACTAGTAC-3' FP: 5'-TGTTAG-3'
RP: 5'-TAGTAC-3'B 5' AGTCTTAG.....ATGCCAGT - 3' FP: 5'-AAGACT-3'
RP: 5'-ACTGGC-3'C 5' CTTGACTA.....GTACAGTCA-3' FP: 5'-CTTGAC-3'
RP: 5'-TGACTG-3'D D 5' GATCTAGC.....TCAAGCAGAC-3' FP: 5'-GATCTA-3'
RP: 5'-CAGACG-3'
