小中大
GIBCO的RPMI1640上就有说明怎么配的：
1.Measure out 5% less distilled water than desired total volume of medium, using a mixing container that is as close to the final volume as possible.
2.Add powdered medium to 15 to 30 ℃ (room temperature) water with gentle stirring.(do not heat water)
3.Rinse out inside of package to remove all traces of powder.
4.Add 2.0g of NaHCO3 per liter of medium.
5.Dilute to a desired volume with water. stir until dissolved.(do not over-mix)
6.Adjust PH of medium to 0.2-0.3 below desired final working PH*: use of 1N HCl or 1N NaOH is recommended.(Add slowly with stirring). After PH has been adjusted, keep container closed until medium is filtered.
7.sterilize immediately by membrane filtration (positive pressure recommend).
* PH units will usually rise 0.1-0.3 upon filtration.
以上是我从冰箱里拿出GIBCO的1640的盒子对着打的，我实际操作中在调PH的时候是充入CO2的，然后再过滤灭菌。一般放4度保存即可，等要使用时，再加入血清及双抗等添加剂。
