I have to work on a protocol to isolate epithelial cells but I have a problem with the formulation of a media.
« Culture medium : (Collection media with 5 % FCS, 120IU/ml of Insulin) »
Collection media is previously defined as a mix of DMEM/Ham's F12 and antibiotics, nothing unusual and I don't need a lot of culture medium (100-200mL for the whole protocol).
I just have a problem with the amount of Insulin (normally, IU means unit of insulin, not international unit). I use Insulin from Sigma :
This Insulin has an activity of 27.5 IU/mg (which is good). The solubility of insulin in water and ethanol is low, 10mg/mL in water : 275 IU/mL for a 10mg/mL solution.
I need a media with 120 IU, which means that 43 % of my final volume comes from the Insulin solution...that's too much.
Maybe I did a mistake or i misunderstood something (units?) but due to the low solubility I don't know (and I didn't find) how to prepare a higher stock solution or an other way to add Insulin?
Thank you in advance for your help,
Have a nice day!
Edited by ollorin, 29 December 2014 - 02:49 AM.