Blue / White Screening of Bacterial Colonies X - Gal / IPTG Plates
Cool autoclaved growth media agar to 50°C .
Add 10 µl X - Gal Solution ( 20 mg / ml ) per 1 mL of Media ( or 2 µl X - Gal Solution ( 100 mg / ml ) per 1 mL of Media ) .
Add 10 µl IPTG ( 100mM ) per 1 mL of Media for a final concentration of 1mM .
Add screening antibiotic of choice ( Ampicillin , Kanamycin , Carbenicillin , etc ) .
Pour plates and allow to cool to room temperature ( usually at least 30 minutes ) before use .
Spread transformed competent cells as desired .
Note : Blue / White Selection plates are generally stable for only 1 week if stored at 4°C in clear sleeves , but may be stored in the dark ( or a dark sleeve ) at 4°C for up to 1 month .
