Protein expression assay

Sample normalization for un-induced/induced E. coli expression sample

Take a sample before induction and in the morning before harvesting the cells after expression. Note: For the after expression the OD600, will be quite high (4-6), perform 10 times dilution in LB media for the OD600 measurement.

0,5/OD600 = X ml required culture.
Example if the OD600 = 0,8 then 0,5/0,8 = 0,625 mL.
1. Spin down calculated amount of cells for 2 mins at 13000 rpm and remove the media.
2. Re-suspend the cells in 40μl dH2O and add 10μl 5xSDS Loading Buffer.
3. Heat the sample for 10 mins at 95°C, and spin down for 1 min at 13000 rpm.
4. Load 5 μl on a 10 well gel.
4. Run SDS-PAGE using standard protocol