Flow Cytometry Core Service

Soluble Protein Quantification

It is possible to quantify the levels of multiple soluble proteins in small sample volumes (less than 50ul) using the BD FACSArray.

Cytometric Bead Array Flex sets (CBA´s) are coated with an antibody to the protein of interest. Beads with specific antibody on the surface are clustered together based on their red fluorescence associated with them. These clusters are captured by the BDFACSArray and are distinguished via a grid (see below where Bead A9 is coated with mouse KC and D7 with mouse IL12p70)


These beads are incubated with the sample, then incubated further in the presence of a capture antibody tagged with the fluorochrome phycoeryithrin (PE). At the same time a set of standards is produced which enables protein quantification between 10-2500pg/ml.

The beads commercially available can detect;

  • Human soluble proteins
  • immunoglobulins; cell signalling
  • Mouse soluble proteins
  • Rat soluble proteins


There are also Functional Beads available, to which your own antibodies of interest can be bound.

Please contact a member of the Flow Cytometry Core Facility for sample preparation advice and a list of charges.