X-Gal
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Jump to navigationJump to searchPreparation of a 5-bromo-4-chloro-3-indolyl β-D-galactopyranoside (X-gal) stock solution.
Safety precautions: Harmful if swallowed. Irritating to eyes and skin. Please refer to the material safety data sheet for further information and safety handling practice.
Typically used for blue/white screening via the lac operon. (Often in conjunction with IPTG, but our TOP10 Competent E. coli cells do not require IPTG).
We use X-gal at 50mM (20mg/mL) dissolved into N,N-dimethylformamide (DMF).
- Weigh 200mg X-gal
- Add 10ml DMF
- Mix till dissolved
- Aliquot into these nice blue tubes (1ml/tube)
Usage: Pipette 40μL X-gal directly onto the top of the LB agar plates and spread out with sterile spatula. Wait to dry before usage.