FDC Forensic Laboratory Procedures 5

Question 1

A forensic DNA laboratory must retain case records after a case is closed. Under most accreditation standards, what is the minimum record retention period?

Accepted Answer

At least as long as the statute of limitations or as required by law, whichever is longer

Answer

Accreditation standards and legal requirements dictate that records must be retained at least as long as the applicable statute of limitations or the legally mandated period, whichever is longer.

Question 2

Which instrument parameter is routinely monitored during CE to ensure consistent DNA fragment sizing?

Accepted Answer

All of the above

Answer

Consistent CE sizing requires monitoring polymer concentration, capillary temperature, voltage ramp, laser power, and detector gain to ensure reproducible electrophoretic conditions.

Question 3

What distinguishes a 'mixture interpretation threshold' from an 'analytical threshold' in forensic DNA analysis?

Accepted Answer

Analytical threshold defines the minimum peak height to be considered a true signal; mixture interpretation threshold sets the minimum height to include a peak as a potential contributor allele

Answer

The analytical threshold (AT) is the minimum peak height above instrument noise, while the mixture interpretation threshold (MIT) is a higher, laboratory-set threshold above which peaks are considered for mixture interpretation.

Question 4

A forensic lab analyst swabs the inside of a buccal (cheek) swab collection device from a reference sample. The swab is then stored in a plastic bag and sealed. What critical error was made?

Accepted Answer

The swab should be air-dried before sealing in the plastic bag to prevent mold and DNA degradation

Answer

Wet biological samples sealed in plastic bags create a moist anaerobic environment that promotes mold growth and bacterial degradation, destroying DNA.

Question 5

In the context of forensic DNA laboratory quality assurance, what is a 'technical review'?

Accepted Answer

A review of case documentation, data, and conclusions by a qualified analyst other than the one who conducted the analysis

Answer

A technical review is an independent examination of a case file, raw data, and conclusions by a second qualified analyst to identify errors before a report is issued.

(FDC) Forensic DNA Certification Practice Test

(FDC) Forensic DNA Certification Practice Test

FDC Forensic Laboratory Procedures 5