HEPES Buffer, 1M pH 7.4 | 500ml
AUD 78.00
Excl.GST
- Product Code: GMES-B-G1
- Availability: In Stock
Tags: Buffer
HEPES is the most widely used Good's buffer for biological work near physiological pH. It provides strong buffering in the pH 6.8-8.2 range without the phosphate precipitation risks of PBS or the primary-amine chemistry of Tris.
Overview
HEPES Buffer, 1M, pH 7.4 - HEPES is the most widely used Good's buffer for biological work near physiological pH. It provides strong buffering in the pH 6.8-8.2 range without the phosphate precipitation risks of PBS or the primary-amine chemistry of Tris.
This product is positioned as a low-friction, ready-to-use stock for laboratories that routinely prepare live-cell imaging buffers, CO2-independent cell-culture supplements, His-tag purification buffers, or CFPS reaction mixtures.
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Use and Applications
- Supplemental buffering of DMEM, RPMI, and other mammalian culture media for work outside a CO2 incubator
- Cell-free protein synthesis reaction mixtures, including PANOx-SP style systems
- IMAC binding, wash, and elution buffers where phosphate precipitation or Tris interference is undesirable
- Enzyme assays, protein handling, and short-term physiological-pH incubations
Specifications
| Item | Specification |
|---|---|
| Bottle | 500 mL sterile borosilicate bottle with PTFE-lined cap |
| Concentration | 1 M HEPES, pH 7.4 at 20 deg C |
| Sterility | 0.2 um sterile-filtered (standard grade); 0.1 um mycoplasma-reduction grade available for cell-culture-supplement use |
| Documentation | Certificate of Analysis and SDS to be supplied with released SKU |
Composition
| Component | Amount / concentration | Function |
|---|---|---|
| HEPES free acid | 1 M; CAS 7365-45-9 | Primary buffering compound |
| KOH or NaOH | q.s. to pH 7.4 | pH adjustment and counter-ion formation |
| Ultrapure water | q.s. to final volume | ASTM Type I solvent |
Instruction
1Dissolve the calculated mass of HEPES free acid in approximately 70% of the final water volume.
2Adjust pH slowly with KOH or NaOH while monitoring temperature; hydroxide addition is exothermic.
3Bring to final volume, verify pH 7.4 +/- 0.05 at 20 deg C, and sterile-filter through 0.2 um PES.
4For working solutions, dilute the 1 M stock to the desired final concentration, typically 10-25 mM.
Note
- HEPES has a measurable temperature coefficient. A solution reading pH 7.4 at 20 deg C will read lower at 37 deg C, which is normally desirable for physiological work.
- For potassium-sensitive assays, request a sodium-adjusted formulation; for sodium-sensitive assays, request the potassium-adjusted formulation.
Cautions
Caution. Avoid exposing HEPES-containing solutions to intense UV illumination during live-cell imaging where reactive oxygen species are a concern.
Caution. Do not assume HEPES and PBS are interchangeable in divalent-cation or metal-affinity workflows.
Caution. Cell-culture use - when HEPES is added to mammalian culture media, request the 0.1 um (mycoplasma-reduction grade) cell-culture variant. Mycoplasma can pass through the standard 0.22 um sterilising filter, so a 0.1 um filtration step is used for media-contact applications. The standard 0.2 um grade is appropriate for IMAC, CFPS, and enzyme-assay use.
Storage and Expiry · Safety
- Store at 2-8 deg C or room temperature away from direct light.
- Unopened shelf life: 24 months from manufacture after QC validation.
- Transport. Ships at ambient temperature; no cold chain required. Protect from freezing and from temperatures above 40 deg C.
- Handling and PPE. Wear a laboratory coat, nitrile gloves, and safety glasses for routine handling. The formulated buffer presents no significant hazard; avoid ingestion and eye contact. Consult the Safety Data Sheet before use.
References
- Good et al. (1966), Biochemistry 5:467-477.
Frequently Asked Questions
Q1. Why use HEPES instead of PBS?
HEPES is a non-phosphate buffer and is less likely to precipitate with Ca2+, Mg2+, Zn2+, or Ni2+ in protein and cell-biology workflows.
Q2. Can the stock be autoclaved?
Sterile filtration is preferred. Autoclaving is usually unnecessary and can introduce avoidable colour or pH drift in high-concentration Good's buffer stocks.
