CGL Laboratory Safety and Procedures 3

Question 1

When conducting a DNA extraction in a genealogical lab, why must the work area be cleaned with a 10% bleach solution before and after each session?

Accepted Answer

To deactivate exogenous DNA that could contaminate samples

Answer

A 10% bleach solution degrades extraneous DNA on surfaces, preventing cross-contamination between samples.

Question 2

What is the purpose of a negative control sample in a genealogical DNA analysis workflow?

Accepted Answer

To verify that reagents and the environment are free of contamination

Answer

A negative control contains no DNA; any signal it produces indicates contamination in the reagents or environment.

Question 3

An archivist discovers that a microfilm roll has become brittle and begins to crack during handling. What is the safest immediate action?

Accepted Answer

Transfer it to a conservation specialist without further handling

Answer

Brittle microfilm requires professional conservation treatment; continued handling risks destroying irreplaceable images.

Question 4

Which type of fire extinguisher is appropriate for an archive lab that contains paper records, electrical equipment, and chemical solvents?

Accepted Answer

Class ABC multi-purpose extinguisher

Answer

A Class ABC extinguisher covers ordinary combustibles (paper), flammable liquids (solvents), and electrical fires — all hazards present in an archive lab.

Question 5

What is the recommended relative humidity (RH) range for storing original genealogical documents to prevent both mold growth and brittleness?

Accepted Answer

30–50% RH

Answer

A range of 30–50% RH inhibits mold while keeping paper flexible enough to avoid cracking from excessive dryness.

(CGL) Certified Genealogical Lecturer Practice Test

(CGL) Certified Genealogical Lecturer Practice Test

CGL Laboratory Safety and Procedures 3