CGL Sample Preparation and Handling 5

Question 1

When a genealogical DNA testing company requests that a donor re-collect a sample due to insufficient DNA yield, what is the most likely root cause?

Accepted Answer

The sample was not collected vigorously enough or was contaminated with food residue

Answer

Insufficient yield is most commonly caused by inadequate cell collection during swabbing or contamination that inhibits extraction, both related to collection technique.

Question 2

In genealogical research, why is it important to document the provenance of a physical sample (such as a lock of hair) before DNA testing?

Accepted Answer

It establishes the chain of custody needed to connect results to a specific ancestor

Answer

Documenting provenance creates the evidentiary chain of custody that allows researchers to credibly link genetic results back to a specific identified ancestor.

Question 3

A genealogical society is planning to collect DNA samples at a public event. Which consent-related document is most critical to prepare in advance?

Accepted Answer

An informed consent form covering data use, storage, and privacy rights

Answer

An informed consent form is legally and ethically essential, ensuring participants understand how their DNA data will be used, stored, shared, and protected.

Question 4

Which characteristic of degraded ancient DNA makes it challenging to use for genealogical identification compared to modern samples?

Accepted Answer

DNA fragmentation and chemical damage (deamination) lead to sequencing errors and short reads

Answer

Over time, ancient DNA undergoes fragmentation into short pieces and cytosine deamination (C-to-T changes), causing sequencing errors and making assembly difficult.

Question 5

When a genealogical researcher receives a scanned image of an archival document and notices the text appears faded, which enhancement approach is safest for the original document?

Accepted Answer

Use multispectral imaging on the original to capture wavelengths invisible to the eye

Answer

Multispectral imaging captures light at wavelengths beyond visible spectrum without touching or chemically treating the document, safely revealing faded text.

(CGL) Certified Genealogical Lecturer Practice Test

(CGL) Certified Genealogical Lecturer Practice Test

CGL Sample Preparation and Handling 5