Anchor positions are positions which delimit the CDR-IMGT and which belong to the neighbouring FR-IMGT. They are shown in squares in the IMGT Colliers de Perles (IMGT Repertoire).
Anchor positions are:
- 26 and 39 for the CDR1-IMGT
- 55 and 66 for the CDR2-IMGT
- 104 and 118 for the CDR3-IMGT
as described in the Definition of the FR-IMGT and CDR-IMGT regions (IMGT Scientific chart).