Some laboratories use IMA, LCMS, ICMA and Beckman Coulter methodology for thyroglobulin AB measurement, and have a reference cutoff of <1.
Vibrant uses the Roche Anti-Thyroglobulin Elecsys electrochemiluminescence (ECLIA), and has a manufacturer-validated reference cutoff of <115.0
For more information on the Roche Anti-Thyroglobulin Elecsys assay, see:
Evaluation of the Highly Sensitive Roche Thyroglobulin II Assay and Establishment of a Reference Limit for Thyroglobulin-Negative Patient Samples https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5574515/pdf/main.pdf