Question

13. The figure in the below is the flow cytometric analysis of red-cell lysed blood sample collected from healthy human. The total number of white blood cells is counted to be 5,000 cells/uL. Provide your answers to following questions. (34pts) Gating of A cells İ/ 5096 | a:5 96 b: 25% , c/ c: 30%) d: 4096 CD3 PE/Cy5 10% 40% . Gating of A cells . g: 30%) h: 15% CD3 PE/Cy5

Answer 1

1) Flow cytometry works on the principle of gating. In initial figure we can find out the cells with varied size and granules.

A represent the lymphocytes (CD3+ cells) , B represent monocytes (CD14+ cells) and C represent granulocytes (CD14)). All these cells are main components of White blood cells. (leukocytes).

Lymphocytes (CD3+ cells) are again gated into cells

a) CD4 cells are helper cells/T4 cells

and b) CD8/T8 are suppressor/ killer cells. which are identified based on the structure and colour

Total number of T helper cells (cells/ $\mu$ l) =

Total number of WBC = 5000 cells/ $\mu$ l

Among WBC lymphocytes are 40 % = 40/100 = 0.04 = 0.04 x 5000

Among lymphocytes ,T helper cells (CD4 cells) = 50 % (f part) = 50/100 = 0.5 of lymphocytes =

=== 0.5 x 0.4 x 5000 =1000 cells/ $\mu$ l

b) Total number of cytotoxic T helper cells (CD8 cells) =

Total number of T helper cells (cells/ $\mu$ l) =

Total number of WBC = 5000 cells/ $\mu$ l

Among WBC lymphocytes are 40 % = 40/100 = 0.04 = 0.04 x 5000

Among lymphocytes ,T helper cells (CD4 cells) = 25 % (b part) = 25/100 = 0.25 of lymphocytes =

=== 0.25 x 0.4 x 5000 =500 cells/ $\mu$ l