Chapter 2: Mass Cytometry and CyTOF XT
CyTOF XT System Components Overview
CyTOF XT User Guide
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The torch assembly is mounted inside an induction load coil supplied with current
generated by radiofrequency (RF) power. This current generates the electromagnetic field
that sustains the plasma.
Figure 23. Load coil shown with torch assembly inside
Sample Ionization
Plasma, consisting of charged particles, is formed by ionization of argon gas within the
electromagnetic field generated in the load coil. First, argon plasma gas flows tangentially
from the outer chamber of the torch holder. RF power supplied to the load coil creates a
strong electromagnetic field as the plasma gas exits the outer chamber of the torch.
A high-voltage spark strips free electrons from the exiting argon atoms. These free electrons
accelerate in the electromagnetic field and collide with enough energy to ionize the argon
gas. Temperatures within the plasma typically range from 5,000 to 10,000 K. When the
aerosolized sample is introduced through the injector into the plasma, the water droplets
are rapidly vaporized. The resulting individual cells are then vaporized to form a cloud of
atoms, which are then ionized. Thus, the plasma contains bursts of ion clouds
corresponding to individual cells that were introduced into the torch in aerosol form.
Figure 24. Plasma production with the plasma torch
