Embryology Laboratory Techniques and Procedures
Core concepts
Master the workflow: oocyte retrieval, denudation, insemination (IVF or ICSI), culture, assessment, and transfer or cryopreservation. Know the purpose of each step and the failure modes. Denudation removes cumulus cells to permit assessment of nuclear maturity; over-exposure to hyaluronidase or mechanical stress harms oocytes.
Handling principles
Maintain temperature (typically 37°C), pH (CO2-dependent), and osmolality. Minimize time outside the incubator and air exposure. Use appropriate pipette diameters; avoid shearing the oocyte or embryo. Document every manipulation.
Traps
- Confusing the purpose of denudation (assessment and ICSI prep) with fertilization.
- Assuming longer culture is always better; extended culture is a selection tool, not a guarantee.
- Forgetting that media and oil must be equilibrated before use.
- Overlooking that handling time and light exposure are quality variables.
Rule of thumb
"Every minute out of the incubator is a stressor." When a question describes an unexpected drop in fertilization or blastulation, first consider handling time, temperature, and pH drift before blaming gamete biology.