You Are Going to Use Flow Cytometry to Determine the Proportion

question 35

Essay

You are going to use flow cytometry to determine the proportion of developing B cells in the bone marrow that are immature, anergic, or mature. You have three monoclonal antibodies specific for three different B-cell surface proteins. The first has specificity for the cell-surface protein CD19, which is expressed by all developing and mature B cells; the second is specific for the Fc region of IgD; and the third is specific for the Fc region of IgM. The antibodies are conjugated to three different fluorescent tags that can be detected and distinguished by the flow cytometer.
A. Use histograms to show your analysis of CD19-positive cells and indicate which part of your histogram you would gate to analyze IgM and IgD expression. Indicate the gated population with an arrow.
B. Using a two-dimensional dot plot, compare the expression of IgD and IgM of these gated cells, and say which of these populations represents (i) immature B cells, (ii) mature B cells, and (iii) anergic B cells.

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Definitions:

Response Rate

Response rate refers to the proportion of people who answer or respond to surveys, questionnaires, or experimental interventions among those who were asked to participate.

Reaction Time

The interval of time between the presentation of a stimulus and the response to it, often used as a measure of sensory and motor performance.

Stimulus

A change in the environment that leads to a change in behavior.

Response

A reaction or reply to a stimulus or situation, which can range from physiological reactions to complex behaviors.