Method for distinguishing between protein variants

A method for distinguishing between protein variants, comprising the steps of providing a FAIMS analyzer region defined by a space between two spaced-apart electrodes;

• providing predetermined conditions within the FAIMS analyzer region;
• producing ions of an analyte protein from a solution having predetermined properties and including the analyte protein;
• introducing the ions of an analyte protein into the FAIMS analyzer region;
• detecting an intensity of the ions of an analyte protein that are transmitted through the FAIMS analyzer region at a predetermined CV value;
• determining at least a difference between the detected intensity and at least a reference value, the reference value relating to an expected intensity at the predetermined CV value for a reference form of the analyte protein;
• and,
• registering the analyte protein as a variant of the reference form in dependence upon the determined differences.

A method of detecting protein variants, comprising the steps of:

• providing a sample derived from a biological source to a FAIMS analyzer;
• sensing an ion output of the FAIMS analyzer;
• and,
• based upon the sensed ion output, identifying one of a presence of and an absence of a variant of the protein molecule indicative of one of a diseased state and an abnormal state in the biological source.