SCYM Cell Sorting 3

Question 1

Which parameter is most directly controlled by changing the nozzle drive frequency on a cell sorter?

Accepted Answer

Droplet formation rate and size

Answer

The nozzle drive frequency determines how rapidly the jet breaks up into droplets, directly controlling droplet size and formation rate.

Question 2

What is the 'breakoff point' in a droplet-based cell sorter?

Accepted Answer

The point at which the continuous liquid jet separates into individual droplets

Answer

The breakoff point is where the continuous liquid stream transitions into discrete droplets, and its stability is critical for accurate and consistent sorting.

Question 3

If a cell sorter's breakoff point is unstable, what is the most likely consequence?

Accepted Answer

Inaccurate delay timing, leading to poor sort purity and yield

Answer

An unstable breakoff point means the actual droplet containing the target cell may not align with the calculated sort delay, causing the wrong droplet to be charged and deflected.

Question 4

What role does the 'sort delay' (or 'drop delay') calibration play in electrostatic sorting?

Accepted Answer

It defines the time between laser interrogation of a cell and the moment that cell reaches the droplet breakoff point

Answer

Sort delay is the number of drops between laser interrogation and droplet breakoff; correct calibration ensures the right droplet is charged at the precise moment it separates from the jet.

Question 5

Which type of collection vessel is preferred when sorted cells must remain viable for downstream culture?

Accepted Answer

Conical tube pre-loaded with culture medium or collection buffer

Answer

Pre-loading collection tubes with culture medium or protein-containing buffer cushions the impact of sorted cells and maintains viability for downstream applications.

(SCYM) Specialist in Cytometry Practice Test

(SCYM) Specialist in Cytometry Practice Test

SCYM Cell Sorting 3