NK Cell Isolation - negative selection kits - (Aug/25/2008 )

Miltenyi or Stem Cell Technologies? Has anyone done a head-to-head comparison of the two in terms of yield and purity? Always use as directed or "stretch"? Am I basically looking at $650 to process 1 x 109 PBMC? I've been leary about going lower on the cocktail, but the cost of these kits has been a cause for concern four our lab. I am attempting to do ChIP assays from nk cells and need as many cells as possible, but am trying not to break the bank...any suggestions?

Flow sort your NKs. For ChIP assays you are going to need as pure of a population as possible, and magnetic separation is going to get you 95% purity on a good day. With a good sorting operator (and good sorter), you can easliy acheive 98-99% purity. Furthermore, you can successfully sort (by flow) 10^9 PBMC in 4hrs. That should give you several million highly pure NKs.