Polyclonal versus monoclonal immunoglobulin-free light chains quantification.

Background: The clinical usefulness of the serum-free light chain assays has expanded since their first description, and further applications other than plasma cell dyscrasia are emerging. Currently, we have the ability to perform the measurements with two certified methods: the Freelite™ assay (The Binding Site Ltd, Birmingham, UK) and the new N Latex free-light chain assay (Siemens, Germany). In the present study, we investigated the impact of free light chain concentrations and structures on their quantification, performed with both tests.