Too few cells migrated through the membrane — barely visible (Transwell Migration / Invasion Assay)

Question

Accepted Answer

Field of view shows only a handful of cells on the lower surface of the insert; counts are too low for meaningful statistics. Common causes: 1) Seeding cell number was too low for this cell line 2) Cell state / vitality is poor 3) Incubation time was too short 4) Chemoattractant in the lower chamber is too weak Solutions: 1) Increase seeded cell number (run a pilot — typically 1 – 5 × 10⁴ cells/insert for migration) 2) Use cells in log-phase, healthy state 3) Extend incubation: 12 – 24 h for migration, 24 – 48 h for invasion 4) Verify chemoattractant concentration in lower chamber (e.g. 10 % FBS)