TransWell Chemotaxis protocol. trans-well chemotaxis method from bioprotocol. The protocol is a method for studying migration towards a concentration gradient of chemoattractant of leukocytes (neutrophils, monocytes and lymphocytes) or other migratory cells. An upper chamber containing a suspension of cells is separated by a membrane from a lower chamber containing medium with chemoattractant. Chemotaxis of the cells from the upper chamber into the lower chamber can be quantified.