Stable Cell Selection with Neomycin - (Jun/11/2009 )

My plasmid that I am using has the neomycin resistance gene and we are using two breast cancer cell lines, MDA-MB 231 and PMC42LA. When I did my kill curve I had to use concentrations of 6mg/ml to get any cell death. This seems really high and I wanted to make sure this was on par with other peoples experiences with Neo. Also at this high of a concentration it turns my media yellow, so I want to make sure that it is truly killing my cells by the antibiotic, not some changes to the media

Thanks

200-400 ug/ml is the usual range, try these concentrations and leave for a little longer, it should work fine.

This was for 12 days and my 1mg/ml plate was growing as well as the control.

bob1 on Jun 11 2009, 06:01 PM said:

i normally use a concentration of 100 ug/ml for my cell culture. at max. i go upto 200. while increasing the concentration gradually i make sure that cells are growing in an expected way.

You got such high resistance concentration (6mg/ml) which is not real. For antibiotics selection, one important issue is to seed the cells as single cells at low density. When cells are confluent, they become very resistant.