| IPTG (Isopropyl-b -D-thiogalactoside) Physical Specifications Formula Weight 238.31 Molecular Formula C9H18O5S Purity >99.5% Melting Point 111 ± 1oC A300 <0.13 A400 <0.006 Molecular Biology Specifications Colorimetric Transformation Assay Pass Recommended Use IPTG is an inducer of B-galactosidase activity in E. coli. It is commonly used in conjunction with X-gal to detect lac gene expression in cloning applications, thus allowing dection of recombinant molecules. Prepare a stock solution of IPTG at 0.1 M (23.8 mg/mL) in sterile distilled water and filter sterilize through a 0.22 micron disposable filter. To either of the below solutions add 3 mL/L IPTG stock solution. When pouring plates add 15 grams bacto-agar per liter. 1). 10X M9 Salts Solution: 60 g Na2HPO4 30 g KH2PO4 5 g NaCl 10 g NH4Cl Adjust the pH to 7.4, add water to a final volume of 1 liter and autoclave. For M9 media add: 100 mL 10X M9 Salts Solution 1 mL 0.01 M CaCl2 2 mL 1.0 M MgSO4 Adjust to a final volume of 1 liter with distilled water. Supplement with (optional): 0.2% Casamino Acids 0.4% Glucose 40 mg/mL Thiamine-HCL 2). 2X YT Media: 16 g/L Tryptone 10 g/L Yeast Extract 5 g/L NaCl Storage Store dessicated at –20oC. Warm to room temperature before opening. Keep tightly sealed. |