TABLE 9.   SOLUTIONS ISOSMOTIC* WITH SEAWATER

*see definitions, below.

SINGLE INGREDIENT SOLUTIONS ISOSMOTIC WITH SEA WATER OF SALINITY 35 o/oo [A1]

GENERAL NOTES:
(1) All solutions containing organic components should be refrigerated to discourage bacterial growth.
(2) For uniformity and viewing ease, concentrations are given throughout this Compendium in mM to two decimal places. However, it is unlikely that there are more than three significant figures in any Compendium table entry.

Values shown = millimolar (mM) concentration = ml 1M stock solution per liter. To determine grams per liter, see Calculations (App. 1) and Formula Weights (App. 2).

Solution No. Ingredient Concentration (mM)
ISO-1 NaCl 530.00
ISO-2 KCl 530.00
ISO-3 CaCl2 340.00
ISO-4 MgCl2 370.00
ISO-5 MgSO4 **900.00
ISO-6 Na2SO4 440.00
ISO-7 NaHCO3 540.00
ISO-8 NaBr 540.00
ISO-9 CsCl 530.00
ISO-10 RbCl 580.00
ISO-11 LiCl 600.00
ISO-12 sucrose 810.00

**the high value 900.00 is due to low dissociation.


*Definitions: The data source, [A1], uses the term "isotonic". The following definitions, derived from [A15], are employed here :
"osmotic concentration" = the osmotically effective concentration of all solutes in a watery medium
"isosmotic media" = media having equal osmotic concentrations
"isotonic medium" = a medium in which a particular cell (or organism) does not change its volume (shrink or swell)

Thus, "isosmotic" and "isotonic" are not equivalent terms. A cell placed in an isosmotic test medium (osmotically effective concentration = that inside the cell) might or might not change volume. For example, if the test medium contains a substance to which the cell is permeable, and at a concentration higher than that within the cell, the substance will enter the cell and produce swelling.