FDC Forensic Laboratory Procedures

Question 1

What is the first step in forensic laboratory evidence processing?

Accepted Answer

Receiving and documenting evidence

Answer

The first and most critical step in forensic laboratory evidence processing is the proper receiving and meticulous documentation of all submitted evidence. This initial step establishes the integrity of the chain of custody, accurately records what was received, and prevents any disputes about the evidence's origin or handling. Without this foundational step, subsequent analyses could be compromised, and the admissibility of evidence in court could be challenged.

Question 2

Why is chain of custody important in forensic labs?

Accepted Answer

Maintain evidence integrity

Answer

Chain of custody is paramount in forensic labs to maintain the integrity and authenticity of evidence. It involves a meticulously documented chronological history of evidence, detailing its collection, seizure, custody, control, transfer, analysis, and disposition. A robust chain of custody ensures that evidence has not been tampered with or contaminated, which is essential for its admissibility and credibility in court.

Question 3

What is the purpose of DNA quantitation in the lab?

Accepted Answer

Measure DNA amount

Answer

The purpose of DNA quantitation in the lab is to accurately measure the amount of human DNA present in a forensic sample. This measurement is a vital step before DNA amplification, as it ensures that the optimal amount of DNA is used for subsequent reactions. Proper quantitation helps prevent issues like PCR inhibition or preferential amplification, leading to more reliable and interpretable DNA profiles.

Question 4

How is contamination prevented in forensic labs?

Accepted Answer

Use clean workspaces and protocols

Answer

Contamination in forensic labs is rigorously prevented through strict adherence to protocols, including the use of clean, designated workspaces, sterile equipment, and personal protective equipment. Separating samples, maintaining one-way workflows, and regular decontamination of surfaces also minimize the risk of transferring foreign DNA. These measures are critical to ensure the integrity of evidence and prevent false or misleading results in forensic investigations.

Question 5

What equipment is essential for PCR in forensic labs?

Accepted Answer

Thermocycler

Answer

A thermocycler is the essential piece of equipment for Polymerase Chain Reaction (PCR) in forensic labs. It precisely controls the rapid heating and cooling cycles required for DNA denaturation, primer annealing, and DNA extension, which are the core steps of PCR. Without a thermocycler, the amplification of specific DNA segments, crucial for generating sufficient DNA from crime scene samples for forensic analysis, would not be possible.

(FDC) Forensic DNA Certification Practice Test

(FDC) Forensic DNA Certification Practice Test

FDC Forensic Laboratory Procedures