Accessible Requires Authentication Published by De Gruyter February 19, 2021

Global FT4 immunoassay standardization. Response to: Kratzsch J et al. Global FT4 immunoassay standardization: an expert opinion review

John E. Midgley

Corresponding author: John E. Midgley, North Lakes Clinical, Ilkley LS29 8PT, UK, E-mail:

  1. Research funding: None declared.

  2. Author contributions: JEM is a former inventor and patent holder for FT4 immunoassays.

  3. Competing interests: Author states no conflict of interest.


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Received: 2021-01-09
Accepted: 2021-02-11
Published Online: 2021-02-19
Published in Print: 2021-05-26

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