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BCMB 406A Lab 2 Exam with
complete solutions latest version
The cells of our immune system have evolved to defend against invading pathogenic
organisms such as bacteria and viruses, but are also capable of recognizing and
destroying____ - CORRECT ANSWER-Our own cancerous cells
What is a chief immune cell that eradicates cancer cells? - CORRECT ANSWER-Killer
T cells: CD8 T-cells.
How do the CD8 T cells find cancer cells? - CORRECT ANSWER-They scan the
surface of cancer cells looking for the presence of mutated proteins. Once these are
recognized, the T cells become activated and destroy the target tumour cells.
T-cells do not recognize full length proteins, instead they recognize___ - CORRECT
ANSWER-Short pieces of protein (peptides) that are bound to MHC molecules on the
surface of the target cell.
T cell recognition of peptide antigen is said to be MHC restricted because_____ -
CORRECT ANSWER-A T-cell will only be activated if it sees peptide complexed with
MHC
What is one way for tumour cells to escape the immune system? - CORRECT
ANSWER-Decrease expression of MHC class I so that they become undetectable to
Killer CD8 T cells
In this lab we assessed the ability of CD8 T cells to: - CORRECT ANSWER-recognize
and respond to their target tumour cells.
Before tested the ability of CD8 T cells to recognize and respond to target tumor cells it
was important that we tested for what? - CORRECT ANSWER-If our tumor cells were
displaying antigen complexed with MHC class I on their surface. If not, the CD8 T cells
will not be able to recognize them.
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The lab was broken into 2 parts: - CORRECT ANSWER-Part 1: Measure tumour cell
MHC I expression
Part 2: Measure T cell response against tumour cells.
Flow cytometry is an advanced technique used to assess the ___ - CORRECT
ANSWER-Phenotype of individual cells in a mixed population, and can be used to
measure characteristics of many different cell types including cells of the immune
system, tissue cells, tumour cells and bacterial cells
Some flow cytometers measure up to 40 different parameters and generate large
amounts of data
Flow cytometry played a vital role in the early identification of what disease? -
CORRECT ANSWER-AIDS
CD4 T cells are selectively depleted.
For flow cytometry, the cells of interest must first be stained with___ - CORRECT
ANSWER-Fluorescent antibodies. Labelling the cells of interest with a cocktail of
different monoclonal antibodies, each with a distinct fluorescent dye (or fluorophore)
A flow cytometer essentially consists of two components: - CORRECT ANSWER-1.
Optics system
2. Fluidics system
What is the optics system used for? - CORRECT ANSWER-To measure the fluorescent
antibodies bound to a cell
What is the fluidics system used for? - CORRECT ANSWER-Ensures cells pass
through the optics system in single file
When staining cells for Flow cytometry, each mAb is specific for...
Why is this important? - CORRECT ANSWER-A different epitope (usually a protein
epitope)
If a cell has proteins X and Y on its surface, it will be stained by TWO different mAbs.
the cell will appear both colours when analyzed (upper right quadrant) which can help
identify cell of interest than if we were to just use one mAb. especially if NON specific
binding is possible. eliminates the chance a cell NOT of interest binds all the antibodies
non specifically.
Flow Cytometry Appendix 2 info - CORRECT ANSWER-
Flow cytometry can ____ and ____ cells - CORRECT ANSWER-define and count
populations of cells
In order to detect and count individual cells, the flow cytometer has a ____ - CORRECT
ANSWER-Fluidics system and a complex optics system.
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Fluidics system mechanics: - CORRECT ANSWER-Comprises a series of tubes, pumps
and valves that function to propel the cells in a single file through the optics system so
they can be counted and measured one at a time.
Optics system mechanics: - CORRECT ANSWER-Consisting of multiple lasers of
different wavelengths, and a series of optical detectors that are set up to measure light
scatter and fluorescence.
When a cell labeled with a fluorescently tagged mAb passes through the interrogation
point of the optics system, two things happen
1. the cell scatters the laser light and the amount of light scattered by the cell is
measured by the optics system. the amount of light scattered is proportional to the size
and granularity of the cell
2. the fluorescent dye bound to the mAb is excited by the laser and it emits a photon of
a particular wavelength that is measured by the optics system. this gives information
about the amount of mAb that is bound to the cell
By using a cocktail of mAbs, each with specificity for different target molecules and
labelled with florescent dyes of different wavelengths (colours) it is possible to measure
what? - CORRECT ANSWER-Expression of numerous cell surface and intracellular
proteins simultaneously.
Monoclonal antibody are ____ - CORRECT ANSWER-specific for a single epitope on
an antigen
Polyclonal antibodies are _____ - CORRECT ANSWER-recognize different epitopes on
the same antigen
Each fluorescent dye (or fluorophore) has a wavelength at which it is _____ and a
wavelength at which it _____ - CORRECT ANSWER-excited
emits
Fluoresence occurs when a fluorophore absorbs _____ - CORRECT ANSWER-High
energy (short wavelength) light and emits lower energy (longer wavelength) light. It is
the wavelength (and frequency) of emitted light that determines the colour of the
flourophore
In flow, the fluorophores are exited by the lasers in the optics system.
Is there a limit to how many different flourophores a flow cytometer can detect?
Why? - CORRECT ANSWER-Yes. (often 8-12 but max is 50)
This is governed by the number of lasers and the number of detectors in a flow
cytometer and is further constrained by spectral overlap
BRAINSCAPE1
BCMB 406A Lab 2 Exam with
complete solutions latest version
The cells of our immune system have evolved to defend against invading pathogenic
organisms such as bacteria and viruses, but are also capable of recognizing and
destroying____ - CORRECT ANSWER-Our own cancerous cells
What is a chief immune cell that eradicates cancer cells? - CORRECT ANSWER-Killer
T cells: CD8 T-cells.
How do the CD8 T cells find cancer cells? - CORRECT ANSWER-They scan the
surface of cancer cells looking for the presence of mutated proteins. Once these are
recognized, the T cells become activated and destroy the target tumour cells.
T-cells do not recognize full length proteins, instead they recognize___ - CORRECT
ANSWER-Short pieces of protein (peptides) that are bound to MHC molecules on the
surface of the target cell.
T cell recognition of peptide antigen is said to be MHC restricted because_____ -
CORRECT ANSWER-A T-cell will only be activated if it sees peptide complexed with
MHC
What is one way for tumour cells to escape the immune system? - CORRECT
ANSWER-Decrease expression of MHC class I so that they become undetectable to
Killer CD8 T cells
In this lab we assessed the ability of CD8 T cells to: - CORRECT ANSWER-recognize
and respond to their target tumour cells.
Before tested the ability of CD8 T cells to recognize and respond to target tumor cells it
was important that we tested for what? - CORRECT ANSWER-If our tumor cells were
displaying antigen complexed with MHC class I on their surface. If not, the CD8 T cells
will not be able to recognize them.
BRAINSCAPE1
, BRAINSCAPE1
The lab was broken into 2 parts: - CORRECT ANSWER-Part 1: Measure tumour cell
MHC I expression
Part 2: Measure T cell response against tumour cells.
Flow cytometry is an advanced technique used to assess the ___ - CORRECT
ANSWER-Phenotype of individual cells in a mixed population, and can be used to
measure characteristics of many different cell types including cells of the immune
system, tissue cells, tumour cells and bacterial cells
Some flow cytometers measure up to 40 different parameters and generate large
amounts of data
Flow cytometry played a vital role in the early identification of what disease? -
CORRECT ANSWER-AIDS
CD4 T cells are selectively depleted.
For flow cytometry, the cells of interest must first be stained with___ - CORRECT
ANSWER-Fluorescent antibodies. Labelling the cells of interest with a cocktail of
different monoclonal antibodies, each with a distinct fluorescent dye (or fluorophore)
A flow cytometer essentially consists of two components: - CORRECT ANSWER-1.
Optics system
2. Fluidics system
What is the optics system used for? - CORRECT ANSWER-To measure the fluorescent
antibodies bound to a cell
What is the fluidics system used for? - CORRECT ANSWER-Ensures cells pass
through the optics system in single file
When staining cells for Flow cytometry, each mAb is specific for...
Why is this important? - CORRECT ANSWER-A different epitope (usually a protein
epitope)
If a cell has proteins X and Y on its surface, it will be stained by TWO different mAbs.
the cell will appear both colours when analyzed (upper right quadrant) which can help
identify cell of interest than if we were to just use one mAb. especially if NON specific
binding is possible. eliminates the chance a cell NOT of interest binds all the antibodies
non specifically.
Flow Cytometry Appendix 2 info - CORRECT ANSWER-
Flow cytometry can ____ and ____ cells - CORRECT ANSWER-define and count
populations of cells
In order to detect and count individual cells, the flow cytometer has a ____ - CORRECT
ANSWER-Fluidics system and a complex optics system.
BRAINSCAPE1
, BRAINSCAPE1
Fluidics system mechanics: - CORRECT ANSWER-Comprises a series of tubes, pumps
and valves that function to propel the cells in a single file through the optics system so
they can be counted and measured one at a time.
Optics system mechanics: - CORRECT ANSWER-Consisting of multiple lasers of
different wavelengths, and a series of optical detectors that are set up to measure light
scatter and fluorescence.
When a cell labeled with a fluorescently tagged mAb passes through the interrogation
point of the optics system, two things happen
1. the cell scatters the laser light and the amount of light scattered by the cell is
measured by the optics system. the amount of light scattered is proportional to the size
and granularity of the cell
2. the fluorescent dye bound to the mAb is excited by the laser and it emits a photon of
a particular wavelength that is measured by the optics system. this gives information
about the amount of mAb that is bound to the cell
By using a cocktail of mAbs, each with specificity for different target molecules and
labelled with florescent dyes of different wavelengths (colours) it is possible to measure
what? - CORRECT ANSWER-Expression of numerous cell surface and intracellular
proteins simultaneously.
Monoclonal antibody are ____ - CORRECT ANSWER-specific for a single epitope on
an antigen
Polyclonal antibodies are _____ - CORRECT ANSWER-recognize different epitopes on
the same antigen
Each fluorescent dye (or fluorophore) has a wavelength at which it is _____ and a
wavelength at which it _____ - CORRECT ANSWER-excited
emits
Fluoresence occurs when a fluorophore absorbs _____ - CORRECT ANSWER-High
energy (short wavelength) light and emits lower energy (longer wavelength) light. It is
the wavelength (and frequency) of emitted light that determines the colour of the
flourophore
In flow, the fluorophores are exited by the lasers in the optics system.
Is there a limit to how many different flourophores a flow cytometer can detect?
Why? - CORRECT ANSWER-Yes. (often 8-12 but max is 50)
This is governed by the number of lasers and the number of detectors in a flow
cytometer and is further constrained by spectral overlap
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