BACTERIAL IDENTIFICATION VIRTUAL
LAB EXAM QUESTIONS AND ANSWERS
(VERIFIED AND UPDATED)
What's the overall purpose of this virtual lab? - ANS Familiarize with science and techniques
used to identify different types of bacteria based on their DNA sequence
What are the four basic steps involved in this bacterial identification lab? - ANS 1. Prepare
sample from patient and isolate whole bacterial DNA
2. Make many copies of desired piece of DNA
3. Sequence the DNA
4. Analyze the sequence and identify the bacteria
What is 16s rDNA and how is it used to identify species of bacteria? - ANS 16s rDNA is a piece
of DNA used for identifying bacteria the region codes for a small subunit of ribosomal RNA.
Identification relies on matching the sequence form your sample against a database of all
known 16s rDNA sequences
As the pathology lab technician what's your task in this virtual lab? - ANS Identify a bacterial
sample received from a clinician
Extracting DNA involves which initial step? - ANS Dissolving the cell wall with a digestive
buffer (in white capped bottle)
@2026/2027 ALLRIGHTS RESERVED.
, What is the wire ring used for? - ANS Obtain a sample form the Petri dish (extracts a colony)
Why are the proteolytic enzymes necessary? - ANS Buffer is a digestive enzyme that east the
cell wall in order to extract the bacterial DNA
Why do you need to inactivate the proteolytic enzymes and how do you do it? - ANS Other
enzymes are used in next step and enzyme is denatured by heating sample in a H2O bath @ 100
°C
After removing the enzymes why do you spin the sample in a centrifuge? - ANS So cellular
debris is spun down in the centrifuge and will appear as a solid deposit (pellet) @ bottom of the
tube
What is the pellet? - ANS Solid debris
What is supernatant? - ANS clear liquid found on top of solid solution after a mixture has
been centiruged contains the inclusion bodies
Where is the DNA? - ANS Contained in the supernatant (liquid) in the PCR tube
What does PCR stand for and what does it do? - ANS polymerase chain reaction; uses a
special type of DNA polymerase to make billions of copies of a targeted sequence of DNA;
widely used in research
What does master mix contain? - ANS Master mix contains all of the components for PCR to
occur, including nucleotides, a special buffer to maintain optimum pH, salts, and MgCl2.
What are primers? Why is a primer added? - ANS short sequences that allow the initiation of
replication of DNA synthesis. Added to bind the 16s rDNA region to the initiate the replication
process
@2026/2027 ALLRIGHTS RESERVED.
LAB EXAM QUESTIONS AND ANSWERS
(VERIFIED AND UPDATED)
What's the overall purpose of this virtual lab? - ANS Familiarize with science and techniques
used to identify different types of bacteria based on their DNA sequence
What are the four basic steps involved in this bacterial identification lab? - ANS 1. Prepare
sample from patient and isolate whole bacterial DNA
2. Make many copies of desired piece of DNA
3. Sequence the DNA
4. Analyze the sequence and identify the bacteria
What is 16s rDNA and how is it used to identify species of bacteria? - ANS 16s rDNA is a piece
of DNA used for identifying bacteria the region codes for a small subunit of ribosomal RNA.
Identification relies on matching the sequence form your sample against a database of all
known 16s rDNA sequences
As the pathology lab technician what's your task in this virtual lab? - ANS Identify a bacterial
sample received from a clinician
Extracting DNA involves which initial step? - ANS Dissolving the cell wall with a digestive
buffer (in white capped bottle)
@2026/2027 ALLRIGHTS RESERVED.
, What is the wire ring used for? - ANS Obtain a sample form the Petri dish (extracts a colony)
Why are the proteolytic enzymes necessary? - ANS Buffer is a digestive enzyme that east the
cell wall in order to extract the bacterial DNA
Why do you need to inactivate the proteolytic enzymes and how do you do it? - ANS Other
enzymes are used in next step and enzyme is denatured by heating sample in a H2O bath @ 100
°C
After removing the enzymes why do you spin the sample in a centrifuge? - ANS So cellular
debris is spun down in the centrifuge and will appear as a solid deposit (pellet) @ bottom of the
tube
What is the pellet? - ANS Solid debris
What is supernatant? - ANS clear liquid found on top of solid solution after a mixture has
been centiruged contains the inclusion bodies
Where is the DNA? - ANS Contained in the supernatant (liquid) in the PCR tube
What does PCR stand for and what does it do? - ANS polymerase chain reaction; uses a
special type of DNA polymerase to make billions of copies of a targeted sequence of DNA;
widely used in research
What does master mix contain? - ANS Master mix contains all of the components for PCR to
occur, including nucleotides, a special buffer to maintain optimum pH, salts, and MgCl2.
What are primers? Why is a primer added? - ANS short sequences that allow the initiation of
replication of DNA synthesis. Added to bind the 16s rDNA region to the initiate the replication
process
@2026/2027 ALLRIGHTS RESERVED.
