SCYM Cell Sorting 2

Question 1

What is the primary purpose of a sheath fluid in a fluorescence-activated cell sorter (FACS)?

Accepted Answer

To hydrodynamically focus cells into a single-file stream through the interrogation point

Answer

Sheath fluid surrounds the sample core and uses laminar flow to hydrodynamically focus cells into a single-file stream at the laser interrogation point.

Question 2

In electrostatic cell sorting, a droplet containing a cell of interest receives a charge. What happens next?

Accepted Answer

The charged droplet is deflected by high-voltage deflection plates into a collection vessel

Answer

Charged droplets are deflected by high-voltage electrostatic plates, directing target cells into the appropriate collection tube while uncharged droplets go to waste.

Question 3

Which sort mode should be selected when recovering the purest possible population is the top priority, even at the cost of yield?

Accepted Answer

Purity mode

Answer

Purity mode aborts the sort decision if a coincident event is detected, ensuring only unambiguously identified target cells are collected.

Question 4

What does the term 'coincidence' refer to in the context of cell sorting?

Accepted Answer

Two or more cells occupying the same droplet at the time of deflection decision

Answer

Coincidence occurs when more than one cell is present in a single droplet, making it impossible to sort the target cell without co-sorting an unwanted cell.

Question 5

The 'abort rate' reported during a sort session primarily reflects which condition?

Accepted Answer

Sort decisions cancelled due to coincident events near or in the same droplet

Answer

The abort rate represents the frequency at which sort decisions are cancelled because a coincident event was detected that would compromise purity.

(SCYM) Specialist in Cytometry Practice Test

(SCYM) Specialist in Cytometry Practice Test

SCYM Cell Sorting 2