Hi Denis, In ``Dictyostelium amoebae and neutrophils can swim"
Nicholas P. Barry and  Mark S. Bretscher (PNAS vol. 107 no. 25 p
11376–11380  (2010)) show how to float Dicty by adding Ficoll.
Sincerely, Carl

On Thu, Dec 12, 2013 at 12:25 PM, David Ratner <[log in to unmask]> wrote:
> Denis,
> Over the years we have separated developing Dicty cell types on Percoll
> density gradients.  The densities we observed were 1.06 g/cc for veg NC4,
> 1.08-1.09 for "light" = prestalk migrating slug cells, and 1.10-1.11  for
> "heavy" = prespore cells.  Note, however, that the densities we observed
> depended upon dissociation conditions (medium composition and temperature)
> immediately prior to centrifugation.  Thus we inferred that osmotic
> properties of the cells were as important to our separation method as was
> their "intrinsic" density.  I've never used glycerol gradients at all for
> this purpose.  Our Percoll separation method is described in detail in:
> Ratner and Borth (1983), Exp.Cell Res. 143, pp. 1-13.
> David
>
>
> On 12/12/2013 11:43 AM, Denis Larochelle wrote:
>
> Hi All,
> Does anyone know the approximate density of dicty cells?  More specifically,
> does anyone have any idea what concentration of glycerol can be used to
> maintain the cells in suspension (without using a shaker)?  I know 0.03%
> agarose can be used but that will not work for our particular application.
> Any input will be greatly appreciated.  Thanks,
> Denis
>
> Denis A. Larochelle
> Associate Professor of Biology
> Director, Program in Biochemistry and Molecular Biology
> Clark University
> 950 Main St.
> Worcester, MA 01610
> 508 793-7631
> [log in to unmask]
>
>
>
>
>
> --
> David I. Ratner
> Alfred Sargent Lee Professor
> Dept. of Biology and Program in BC/BP
> Amherst College, Amherst MA, 01002
> 413-542-2248



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