EDTA concentration in PBS-EDTA? - (Dec/11/2007 )

What is the typical concentration of EDTA in PBS-EDTA? And, how high can the concentration of EDTA go?

we usually have EDTA in PBS at 1mM.

I am actually looking for a way to resuspend fibroblast cells without using Trypsin or any other protease.
I need to analyze membrane proteins.

How long do you guys suggest leaving the cells in PBS/EDTA (EDTA at 5mM)? Seems 20min is not enough.

Sigma sells a non-enzymatic cell lifting reagent. I think other company does that too. It has more than EDTA.

I use PBS-Glucose(10mM)-EDTA(3mM) to detach macrophages, always thought the glucose is there just to protect the cells, but might also be helping detaching who knows.