Mass Cytometry, commercialized by the company DVS Sciences, in the instrument called the CyTOF is a newly emerging technology in the field of flow cytometry. This technology replaces traditional fluorescent-labeled antibodies with highly purified, stable isotopes with very well characterized mass values. This extends the power of flow cytometry from 14-18 fluorochromes to over 40+ simultaneous parameters.
The advantage of mass cytometer include:
● Increased number of parameters measured
● No equivalent autofluorescence – cells do not contain stable lanthanide ions
● Minimal ‘compensation’, mostly due to oxidation of some metals, which is predictable
Some limitations of the mass cytometer include:
● No equivalent forward or side scatter
● Slower acquisition rate (1,000 cells/second vs 10,000 cells/second on conventional flow cytometers)
● Cells are destroyed (vaporized by plasma)
● High content data needs new analysis techniques
At the heart of the CyTOF is a very sensitive Time of Flight (TOF) mass spectrometer. This detection system can resolve 143Nd from 144Nd or 152Sm from 153Eu and so on. Cell preparation for CyTOF analysis is similar to traditional flow cytometry, except at the end the cells must be fixed and resuspended in very pure water. These cells are introduced into the CyTOF, where they are vaporized by an induced charge-coupled plasma and ionized before being sent to the TOF. There the ion cloud is interrogated and, like in traditional fluorescent flow, the signal intensity detected is proportional to the amount of antibody on the surface of the cell.