Generating Vero suspension cells, will be a challenge and there are several aspects which will be very important to consider:
· Media should include fluids which reduce shear forces, if the cells are being grown in a shaking format
· It may be necessary to screen many cells, to find a clone which might have the ability to grow in a suspension format
· It may be necessary to continually passage cells, until the suspension adapated cells finally prevail
· May want to try formulations of media designed for suspension cells
Here is a link with some additional information that may be helpful - http://www.lifetechnologies.com/us/en/home/references/protocols/cell-culture/serum-protocol/adaptation-of-cell-cultures-to-a-serum-free-medium.html