IPTG Chemical Properties

Melting point:

105 °C

alpha 

-31 º (c=1, water)

Boiling point:

350.9°C (rough estimate)

Density 

1.3329 (rough estimate)

refractive index 

1.5060 (estimate)

storage temp. 

2-8°C

solubility 

Soluble in Water or Methanol.

pka

13.00±0.70(Predicted)

form 

Crystalline Powder

color 

White

Water Solubility 

soluble

Merck 

14,5082

BRN 

4631

Stability:

Stable. Incompatible with strong oxidizing agents.

InChIKey

BPHPUYQFMNQIOC-NXRLNHOXSA-N

CAS DataBase Reference

367-93-1(CAS DataBase Reference)

EPA Substance Registry System

Isopropyl .beta.- thiogalactoside (367-93-1)

Safety Information

Hazard Codes 

Xn,Xi

Risk Statements 

19-40-66-36/37/38

Safety Statements 

23-24/25-36/37-22-36/37/39-27-26

WGK Germany 

3

F 

10

TSCA 

Yes

HS Code 

29389090

MSDS

• Language:English Provider:IPTG
• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS
• Language:English Provider:ALFA

IPTG Usage And Synthesis

Description

IPTG (also known as Isopropyl-β-D-Thiogalactopyranoside) is a molecular biology reagent that functions as an inducer of galactosidase activity by binding to and inhibiting the repressor. It is a molecular mimic of allolactose, a lactose metabolite that triggers transcription of the lac operon, and it is therefore used to induce protein expression where the gene is under the control of the lac operator. IPTG cannot be hydrolyzed or broken down by the E. coli therefore the concentration remains constant during cell replication. IPTG is often used at a final concentration ranging from 0.5-1.0 mM. X-Gal is often used with IPTG since it provides an easy visual method to monitor whether protein expression has occurred. X-Gal as the name implies contains a galactose group that once metabolized causes a bright blue color change.

Chemical Properties

White crystalline powder

Uses

Isopropyl-β-D-thiogalactoside is used as a reagent in molecular biology. It is used as an effective β-galactosidase inducer of protein expression where the gene is under the control of the lac operator. It is used with 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside to identify the non-recombinant plasmid in cloning experiments by blue-white screen methodology.

Definition

ChEBI: Isopropyl beta-D-thiogalactopyranoside is an S-glycosyl compound consisting of beta-D-1-thiogalactose having an isopropyl group attached to the anomeric sulfur.

Application

IPTG (Isopropyl-β-D-thiogalactopyranoside) is a galactose analogue not recognized by β-galactosidase. IPTG is a non-metabolizable galactose analog that induces expression of the lac operon in Escherichia coli. It is a commonly used reagent in cloning procedures that require induction of b-galactosidase activity and is used in conjunction with X-Gal. It is commonly used in cloning procedures that require induction of β-galactosidase activity. It is also used in conjunction with X-Gal or Bluo-Gal in blue-white selection of recombinant bacterial colonies that induce expression of the lac operon in Escherichia coli. IPTG functions by binding to the lacI repressor and altering its conformation, which prevents the repression of the β-galactosidase coding gene lacZ.

Preparation

a synthetic method of isopropyl-β-D-thiogalactoside. The steps are as follows:
Step 1: Dissolve β-D-galactose pentaacetate in any organic solvent of methylene chloride, chloroform or 1,2-dichloroethane, and add Lewis acid (boron trifluoride ether, (Aluminum trichloride, zinc chloride) catalyst and potassium ethylxanthate or sodium ethylxanthate are reacted to obtain tetraacetylgalactose ethylxanthate after treatment.
Step 2: Dissolve tetraacetyl galactose ethyl xanthate, 2-bromopropane and sodium carbonate in methanol or ethanol at a temperature of 20°C to 80°C and react for 4-6 hours to obtain isopropyl group after treatment Isopropyl-β-D-thiogalactoside.

General Description

Inducer for β-galactosidase, an enzyme that promotes lactose utilization. Use in conjunction with X-Gal. Molecular Biology grade.
Stock solutions:
X-Gal: 20 mg/ml in DMF
IPTG: 20 mg/ml in water
Use 4:1 (X-Gal:IPTG)
Assay: ≥99%
Dioxane: None detected
Melting point: 110-114°C
Specific rotation [a]25/D (1%, water): -34.0 to -29.0°
Intended for laboratory and manufacturing use only. Not for drug, food, or household use.

Solubility in organics

IPTG is soluble in organic solvents such as ethanol, DMSO, and dimethyl formamide (DMF). The solubility of IPTG in ethanol and DMSO is approximately 20 mg/ml and approximately 30 mg/ml in DMF.

storage

Store powder at -20°C away from direct sunlight. Once opened and recapped, place container in a low humidity environment at the same storage temperature. Protect from moisture and light by keeping container tightly closed.

IPTG(367-93-1)Related Product Information

• Galacto-oligosaccharides
• α-galactosidase
• Thioacetamide
• Sodium thiosulfate
• Dulcitol
• Isopropyl alcohol
• Isopropyl acetate
• TRIGALACTURONIC ACID
• ISOPROPYL LAURATE
• D-GALACTOSE 1-[2-(2-AZIDOETHOXY)ETHOXYETHYL]-2,3,4,6-TETRA-O-ACETATE
• Isoprinosine
• ISOPROPYLMAGNESIUM CHLORIDE
• Isopyrin hydrochloride
• 2-(2-BROMOETHOXY)PROPANE
• ISOPROPYLCYCLOHEXANE
• isopropylsulphamoyl chloride
• Proteinase K
• ALDEHYDE DEHYDROGENASE