NOTE - Use arachidonic acid from Biomol (# FA-003)
1) Make up the appropriate concentration of AA in 100% ethanol.
2) Add 1µl of phenol red solution.
--> The solution should appear yellow since the free acid has not been neutralized as yet.
3) Add 1 µl at a time of 50% NaOH-H2O (1:1) and vortex after each addition.
4) Once a pink color has been attained, the solution is "neutralized."
--> At this point, the pH should be ~8-9; this should not be too critical however, since cells will be treated with such little volume of this solution.