Effector Mechanisms of Humoral Immunity Flashcards
Where are Antibodies produced?
Antibodies are produced by B lymphocytes and Plasma cells in the Lymphoid organs and Bone Marrow.
Where do Antibodies perform their effector functions?
Antibodies perform their effector functions at sites distant from their production.
What is Flow Cytometry and Fluorescence?
Flow Cytometry takes advantages of the fact that certain dyes (such as fluorescein and rhodamine) absorb light at one wavelength and emit it at another characteristic wavelength.
With proper excitation sources and filters, they can be detected and distinguished.
These dyes can be attached to Antibodies without altering their affinity. By using different filters and dyes, it is possible to look simultaneously at multiple antigens or specificity.
What is the difference beween direct and indrect staining?
Fluorescent Antibody staining of cell membrane molecules or tissue section can be direct or indirect.
Direct staining: The specific Antibody (the primary Antibody) is irectly conjugated with dye.
Indirect staining: The primary Antibody is unlabeled and is detected with an additional fluorochrome-labeled reagent.
Fluorescent Activated Cell Sorter (FACS) uses a laser beam and light detector to count single intact cells in suspension.
Simplest instrument counts each cell as it passes the laser beam andr ecords the level of fluorescence the cell emits.
Analysis of FLOW: When the instruemnt is used to determine which and how many members of a cell population bind fluorescently labeled Antibodies.
What is analysis in 1 Dimension?
The data are expressed as a plot of the # of cells vs. the fluorescent intensity of the cells. The fluorescent intensity indicates the amount of the Antigen present on the cell surface.
This appraoch only allows analysis of the expression of 1 Antigen.
What is 2 Dimensional analysis?
It is the analysis of the simultaneous expression of 2 different Antigens on the cell surface.
In a dot plot, each dot reprsents the x and y coordinates of one cell.
B Antigen expressed | Both Antigens expressed
—
No Antigens expressed | A Antigen expressed
