How should cells be cultured prior to setting up the 3-D culture?
FAQ from Trevigen
Cells need to be healthy and actively dividing in 2-D culture. Cells should be passaged two or three times after resuspension from cryopreservation, and they should never surpass 80% confluency during each passage. Cells should also be assessed using trypan blue, and they should exhibit less than 5% staining.