Hi,

I am currently working with SUM 159 and 149 cell line. I received the cells from a collaborator and thawed them with proper technique. They grow fine. After the first passage, many dot like particles (fig 1) appear in the flask culture. The cells on the bottom are still growing fine, but due to the particles I am facing problem while forming spheroids (particles cover the well and imaging is not clear) or even 2D cultures. The collaborators suggested me to reduce the trypsinization time, which I did, but did not get rid of those particles. I also autoclaved my incubator to see if there is any contamination, but still those floating particles appear. Could anyone suggest me what's going on?

Thank you for your time and help.

Sunil

I am using following media.