Home Cell Biology Transwell Migration Assay | CSU BMB Exploring Biochem
Steps
  1. 1 Prepare and count cancer cells 02:48
  2. 2 Set up transwell migration chambers 04:39
  3. 3 Incubate cells to allow migration 05:53
  4. 4 Clean and remove non-migrated cells 06:16
  5. 5 Fix cells with paraformaldehyde 07:23
  6. 6 Stain fixed cells with methylene blue 07:59
  7. 7 Count migrated cells and analyze results 09:18
Cell Biology YouTube (Curated Tutorials)

Transwell Migration Assay | CSU BMB Exploring Biochem

Protocol
Difficulty
intermediate

Steps

1
Prepare and count cancer cells

Split cells using Trypsin and count them to obtain an accurate cell count. Centrifuge the cells and resuspend the cell pellet in starvation media, ensuring equal cell numbers across all treatment and control wells.

▶ 02:48
2
Set up transwell migration chambers

Add starvation media with epidermal growth factor (chemoattractant) to the lower chambers and starvation media with cell division inhibitor to the upper chambers. Seed a fixed number of prepared cells into each upper chamber.

▶ 04:39
3
Incubate cells to allow migration

Incubate the transwell plate at 37°C with 5% CO₂ for 24 hours to allow cancer cells to migrate through the porous membrane toward the chemoattractant.

▶ 05:53
4
Clean and remove non-migrated cells

Use cotton swabs to carefully clean the upper membrane surface of all cells that did not migrate through the pores. Remove the media from the upper chamber.

▶ 06:16
5
Fix cells with paraformaldehyde

Transfer each transwell to a well containing 4% paraformaldehyde fixative and incubate for 30 minutes to fix the migrated cells on the lower membrane.

▶ 07:23
6
Stain fixed cells with methylene blue

Add methylene blue stain to wells containing the transwells, ensuring the membrane is fully covered with stain. Incubate for 20 minutes to color the migrated cells.

▶ 07:59
7
Count migrated cells and analyze results

Rinse the stained membranes and observe under microscope. Capture 30 images (fields) per treatment, count cells in each field, calculate averages, and compare migration rates between treated and control samples.

▶ 09:18

🚨 Failure Case Library (5) + Submit your own case

severe
Too few cells migrated through the membrane — barely visible
Field of view shows only a handful of cells on the lower surface of the insert; counts are too low for meaningful statistics.
💡 4 · ✓ 4
moderate
Too many migrated cells — packed solid, can't count
Lower surface is densely covered with cells that fuse together; individual cells cannot be counted.
💡 4 · ✓ 4
moderate
Staining is too light — cells hard to discern
Cells on the membrane are very faintly colored; impossible to count confidently or photograph clearly.
💡 5 · ✓ 4
moderate
Staining is too dark — high background obscures cells
Background is deeply stained; non-specific stain swamps the cells; hard to distinguish migrated cells from background.
💡 4 · ✓ 4
moderate
Cells are unevenly distributed across the membrane — poor reproducibility
Different fields of view show wildly different cell density; replicate inserts disagree.
💡 4 · ✓ 4
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