Hygromycin in cell cultures

[Phil Barker]

We generally change hygromycin every 3rd day. Different cell lines 
show different death rates but generally expect it to take about 
7-12 days. EC50's to hygro also vary a great deal - lymphoid cells 
such as U937 are particularly resistant, some times requiring up to 
800 ug/ml for complete selection - best to titrate up to 1000 ug/ml 
to be certain. 
Good luck