blastomere
Pronunciation: BLAS-toh-meer
Individual cell within an early-stage embryo, typically biopsied on day 3 for genetic testing.
Full Definition
A blastomere is one of the cells formed during the early cleavage divisions of a fertilized embryo, typically referring to the 6-8 cells present on day 3 of embryonic development. In reproductive genetics, one or two blastomeres may be removed for preimplantation genetic testing without significantly compromising embryo viability. This biopsy technique has largely been superseded by trophectoderm biopsy at the blastocyst stage due to improved accuracy and reduced impact on embryo development. Blastomere biopsy results may be affected by embryonic mosaicism.
Usage
Usage note: Distinguish from blastocyst, which is a later developmental stage.
In Context
- "Single blastomere biopsy was performed on day 3 embryos for PGT-M analysis." — Laboratory procedure note
- "The genetic counselor explained that blastomere testing has higher rates of inconclusive results compared to trophectoderm biopsy." — Patient consultation note