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For laboratory research use only.
$19.00
Sku: IB0168-1g
Availability:
AVAILABLE
In stock & estimated to ship in 3-7 days by July 10, 2026
Description
IPTG (Isopropyl β-D-1-thiogalactopyranoside) is a highly pure, non-metabolizable analog of galactose that inactivates the lac repressor to induce the synthesis of β-galactosidase in E. coli. The expression of cloned genes under the control of the lac operon is efficiently induced by IPTG. It also serves as a substrate for thiigalactoside transacetylase and has been reported to induce penicillinase in bacteria.
IPTG is commonly used in molecular cloning procedures that require induction of β-galactosidase. It is most often utilized in conjunction with Biofargo X-Gal for blue/white colony screening, or Magenta-Gal for red/white colony screening of bacterial colonies.
IPTG is an essential reagent for the induction of recombinant proteins. In these expression systems, the protein of interest is encoded downstream of the IPTG-inducible promoter. Upon the addition of IPTG, robust protein expression is induced in the cell culture. The culture can then be lysed, and the expressed protein can be purified through various methods, including His-Tag or GST purification systems.
Biofargo IPTG is Dioxane-Free and manufactured from a synthetic, non-animal origin to ensure the highest experimental reproducibility.
Specifications
| Chemical Name | Isopropyl β-D-1-thiogalactopyranoside |
| CAS Number | 367-93-1 |
| Formula | C9H18O5S |
| Molecular Weight | 238.30 g/mol |
| Purity / Quality | ≥99.0% (Dioxane-Free) |
| Grade | Molecular Biology Grade |
| Storage/handling | Store desiccated at -20°C. Protect from light. |
| PubChem CID | 656894 |
Feature
- IPTG acts by mimicking the natural inducer allolactose: it binds to the lac repressor (LacI) and causes its release from the lac operator site, allowing transcription of downstream genes under the lac promoter.
- Because IPTG is not metabolized by the cell, its concentration remains stable over time, enabling sustained induction rather than being depleted.
- In recombinant protein expression systems (for example vectors using T7 promoter under lac operon regulation), addition of IPTG triggers expression of the gene of interest downstream of the inducible promoter.
- IPTG is often used in colony screening (e.g., blue/white screening) in combination with chromogenic substrates such as X‑Gal: in this context IPTG activates β-galactosidase expression which cleaves X-Gal to yield a colored product.
- Because of the consistency and high quality of Biofargo’s IPTG, it supports reproducible gene induction workflows and reduces variability associated with induction reagent quality.
Applications
- Gene expression induction in systems controlled by the lac operon
- Blue-white screening (with X-Gal) for recombinant DNA identification
- Controlled production of recombinant proteins
- Timed gene activation for functional studies
- Regulatory input in synthetic biology circuits
Reconstitution
100mM IPTG stock solution
- Weigh 0.238 g of IPTG
- Add 10 mL sterile H2O. Dissolve completely.
- Prewet a 0.22 µm syringe filter by drawing through 5-10 mL of sterile H2O and discard water.
- Sterilize IPTG Stock through the prepared 0.22 µm syringe filter.
- Store in 1 mL aliquots at -20°C for up to 1 year.
Storage
Store powder IPTG desiccated at -20°C. Protect from light.
For IPTG stock solution, store in 1 mL aliquots at -20°C for up to 1 year. IPTG is readily dissolved in sterile water.
Documents
FAQ
How does IPTG work?
IPTG, which is similar to the lactose metabolite allolactose, induces the lac operon by binding to the lac repressor. Once IPTG binds to the lac repressor, a conformational change occurs, causing the lac repressor to dissociate from the lac promoter. Once the lac repressor dissociates, RNA polymerase binds to the promoter to initiate expression. It is frequently paired with chromogenic substrates like X-Gal for blue/white colony screening.
What concentration of IPTG should be used for expression?
Most papers recommend using between 0.1-1.0mM IPTG for expression. However, the optimal amount depends entirely on your target protein. It is best to run an IPTG titration ranging between 0.01-1.0mM and compare expression levels using SDS-PAGE. Keep in mind that excessively high concentrations of IPTG can lead to the formation of inclusion bodies.
Why should I use IPTG over lactose?
IPTG is non-metabolizable, meaning its concentration remains stable throughout the experiment and does not get consumed or depleted by the bacteria, leading to sustained protein induction.
When should I add IPTG during culture growth?
You should typically add IPTG at the mid-log growth phase (OD600 ≈ 0.4–0.6). This ensures that the bacterial cells are healthy, actively dividing, and capable of high-yield protein expression.
Do I need to autoclave IPTG?
No—filter sterilize only. IPTG is heat-sensitive and will degrade under high temperatures, so it should never be autoclaved.
Does IPTG degrade over time?
IPTG is highly stable when stored properly as a powder (desiccated at -20°C, protected from light). For liquid stock solutions, repeated freeze-thaw cycles should be avoided to prevent gradual degradation.
Can IPTG be reused after thawing?
The best practice is to prepare single-use aliquots of your IPTG stock solution. Do not refreeze leftovers once thawed to avoid risks of degradation or contamination.
Can IPTG be toxic to cells?
Yes, IPTG can exhibit toxicity at unnecessarily high concentrations or in overly sensitive bacterial strains. If toxicity or cell death occurs, try lowering the IPTG concentration or utilizing auto-induction media alternatives.
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Disclaimer
For laboratory research use only.
When can I expect my order to ship?
Most orders are filled and shipped within 2-3 business days from the time they are received.
Our standard shipping usually take 2-5 days.
We also provide express shippping for time-sensitive deliveries.
Email contact@biofargo.com if you have any requirements.
