Fd fragment

https://doi.org/10.1351/goldbook.13139
Heavy chain portion of an immunoglobulin (Ig) N-terminal to the papain hydrolysis site, after reduction and separation of the light chain portion.
See also: Fab fragment
Source:
PAC, 2012, 84, 1113. (IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)) on page 1164 [Terms] [Paper]