The description in this example provides one manner in which RNAlater™ can be prepared. First, one should prepare or obtain the following stock solutions and reagents: 0.5 M EDTA disodium, dihydrate (18.61 g/100 ml, pH to 8.0 with NaOH while stirring); 1 M Sodium Citrate trisodium salt, dihydrate (29.4 g/100 ml, stir to dissolve); Ammonium Sulfate, powdered; Sterile water.

In a beaker, combine 40 ml 0.5 M EDTA, 25 ml 1 M Sodium Citrate, 700 gm Ammonium Sulfate and 935 ml of sterile distilled water, stir on a hot plate stirrer on low heat until the Ammonium Sulfate is completely dissolved. Allow to cool, adjust the pH of the solution to pH5.2 using 1 M H₂SO₄. Transfer to a screw top bottle and store either at room temperature or refrigerated.

Final concentrations:

25 mM Sodium Citrate
10 mM EDTA
70 g ammonium sulfate/100 ml solution
pH 5.2