The SARS-CoV-2 UTAB FS is a new particle enhanced immunoturbidimetric assay (PETIA) for the quantitative determination of total antibodies to the SARS-CoV-2 spike (S) protein receptor binding domain (RBD) in human serum. The assay provides a wide measuring range, high specificity and sensitivity, and is well-suited for use on almost all common clinical chemistry analyzers.