Micromanipulation and Assisted Reproductive Technologies
Core concepts
ICSI involves immobilizing sperm, aspirating it, and injecting it into the oocyte cytoplasm after breaching the zona and oolemma. Know the sequence and the purpose of each step. Also understand assisted hatching (mechanical, chemical, or laser) and its indications, plus the concept of sperm selection techniques.
Technique and safety
Maintain stable micromanipulator alignment, appropriate injection and holding pipette sizes, and correct Piezo or bevel settings. Avoid excessive cytoplasmic disturbance. Document injection outcomes and any abnormalities.
Traps
- Confusing immobilization (damaging the tail membrane) with killing the sperm.
- Assuming assisted hatching guarantees implantation.
- Forgetting that ICSI bypasses natural selection and may carry different risk profiles.
- Mixing up holding versus injection pipette functions.
Rule of thumb
"Immobilize, aspirate, breach, inject, withdraw gently." If a question describes failed fertilization after ICSI, consider oocyte maturity, sperm viability, and technical factors such as injection depth or oolemma breach before assuming gamete incompatibility.