Dictyostelium discoideum

[ref. ID; 7421]

Test system

Osmotic stress

Strains

Axenic strain AX-3, osmotic activity of approximately 200 mOsM.

Stress conditions

Low Osmotic Buffer L: 5 mM NaPi (pH 6.5) + 5 mM glucose +1 mM MgCl2 (calculated ideal osmolarity ~20 mOsM).
Medium Osmotic Buffer M: Buffer L + 75 mM NaCl (~170 mOsM).
High Osmotic Buffer H: Buffer L + 150 mM NaCl (~320 mOsM).
Buffer Z: 1mM MgCl2 + 5 mM glucose (~8 mOsM).

Test design

Cells were harvested in the mid-exponential phase of growth (5x10E6/ml), washed with Buffer M, pelleted, and resuspended at 5x10E7/ml in test buffer. Room temperature.

Measurements/observations

Amine release (umol/cells) and amino acid analysis.