Overview

Mass cytometry is a variation of conventional flow cytometry using metal tagged antibodies instead of fluorochromes and detection by time of flight of discrete masses of the metal tags. The lack of any significant mass spectral overlap (no need for compensation) and auto-fluorescence background makes this technology uniquely suited for unravelling high dimensional functional and phenotypic correlations at the single cell level, accelerating biomarker discovery and drug screening.

Fluidigm
CyTOF Fluidgm

The NIHR BRC Flow Core was the first to successfully establish a Mass Cytometry service in the UK and nowoperates two mass cytometers the upgraded CyTOF I (see, left) and the Helios (see above).

The core offers a full service including custom antibody labelling, panel design, acquisition, troubleshooting and high dimensional data analysis, which is supported by a dedicated bioinformatician for custom analysis and a highly experienced CyTOF specialist. In addition to standard analysis software the BRC Flow Core also has a licence to CytoBank (Spade, Visne, data sharing). For access please contact the head of the BRC Flow Core (Susanne.Heck@gstt.nhs.uk).

With over 100 detection channels, currently 38 stable isotopes for antibody tagging and more than10 markers for barcoding and cellular identity we are able to deep phenotype clinical and research samples from internal and external clients. Staining protocols and workflows are similar to traditional fluorescent Flow Cytometry as shown in the figure below (modified from Fluidigm).

CYTOF diagram

The figure above gives a brief summary on how mass cytometry works.  A liquid sample containing fixed cells labelled with metal-tagged antibodies/probes (A) is introduced into a nebulizer at a rate of ~500 cells/sec creating an aerosol (B) and then transported towards an argon plasma (C) where the cells are vaporized, atomized and ionized.  After selective removal of  low mass ions in the quadrupole  (D),  the ion cloud containing the isotopic metal tags used for labelling enters the TOF chamber where probes are separated by time of flight based on their mass to charge ratio as they accelerate towards the detector (E).  The time-resolved detector measures a mass spectrum that corresponding to the identity and quantity of each isotopic probe on a per-cell basis (F).  Data is saved in FCS format (G) and can be analyzed using third party software as mentioned above (H).

Further information

The BRC CyTOFs are operated as a facility service. If you are a new user or are adding another panel to your analysis scheme please setup a meeting with the core to discuss your experiment, panel design and analysis needs. To do so, please send us an email at brcflowcore@gstt.nhs.uk

To join the UK CyTOF user group please visit us at www.cytof.uk