50 mM glucose

Glucose has two forms, and here we are using d-glucose[[http://en.wikipedia.org/wiki/Glucose]] powder, also known as anhydrous dextrose. (BTW - This is one of the "donated" compounds that was collecting dust in a colleague's cabinet.)


== Making 1M glucose stock solution ==

D-Glucose is C_6H_{12}O_6, with a molar mass of 180.16 gr/mole. So, '''to make 1M d-glucose stock solution''' one uses
1 liter distilled water
180.16 grams of anhydrous dextrose 

Since we did not need an entire liter of the 1M glucose stock, the following recipe sufficed:
50 ml distilled water
(50/1000)(180.16) = 9.0 gr anhydrous dextrose

A beaker, magnetic stir bar, and magnetic stir plate are handy. No heat is needed for this sugar-water to become a 1M solution, but a little warmth won't hurt. The rapid dissolution of the d-glucose at this concentration makes it unlikely that you'd have it on the heat long enough for it to caramelize.


== Using 1M glucose stock to achieve a 50mM final concentration of glucose in 100ml of Solution I ==
Now, we must add some of the 1M glucose stock to make the final concentration 50mM in 100ml of Solution I. How much should we add? Use the formula 
  C1 '''*'''  V1 = C2 '''*''' V2
where ''''*'''' is the symbol for multiplication over the real numbers,
C1 is the stock solution's concentration - 1M, 
V1 is the unknown quantity that we wish to discover (in this particular example),
C2 is the final concentration of glucose in Solution I being prepared, and
V2 is the final volume of the solution being prepared - in this case, 100ml.

'''Important Note''': The units of measure one selects for volume and concentration must be the same on both sides of the equation. If we use 50mM concentration for C2, then we must use 1000mM in place of 1M for the working stock concentration, C1. Likewise, if we wish to use volume measured in ml for V2, then we will obtain an answer for V1 that is in ml. One does not have to use ml just because one used mM - one could measure volume in liters and concentration in millimoles.