Name: Poly(ethylene glycol) methyl ether 500 (PEG 500 MME)
Brand: Molecular Depot
SKU: B2010648
Price: 250.00 USD
Availability: InStock

<h2>What are biochemical buffers and solutions?</h2>
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Biochemical buffers and solutions are aqueous systems formulated to resist pH change within a defined working range, used across research to maintain consistent pH and ionic conditions during protein storage, cell lysis, enzyme reactions, affinity chromatography, and other workflows where pH stability is critical. Common examples include PBS (phosphate-buffered saline) for biological sample dilution and cell culture washing, HEPES (N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid) for pH-sensitive enzyme reactions, Tris-HCl for protein and nucleic acid storage, and PIPES and MES for specific pH range applications.
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<h2 dir="ltr">What you will find:</h2>
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TRIS Reference Buffers: High-purity crystalline matrix agents for stable physiological pH maintenance in complex biological assays.
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1X TE Buffer Systems: Standardized Tris-EDTA configurations optimized for long-term nucleic acid preservation and stable dilution workflows.
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10X Tris-Glycine-SDS Concentrate: Premium pre-mixed running buffer packs engineered for seamless polyacrylamide gel electrophoresis protein separation.
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DTT Reducing Agents: High-grade Dithiothreitol solutions prepared for the efficient cleavage of protein disulfide bonds during denaturing workflows.
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<h2>How to choose biochemical buffers and solutions</h2>
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Match your buffer to the required pH working range
Each common biochemical buffer has an effective buffering range tied to its pKa: HEPES (pKa 7.5) is excellent for near-physiological pH 7.0&ndash;8.0 conditions; PIPES (pKa 6.8) and MES (pKa 6.1) cover slightly acidic ranges; Tris-HCl (pKa 8.1) is widely used at pH 7.5&ndash;9.0 for nucleic acid and protein storage; and PBS provides a defined phosphate-based physiological buffer at pH 7.4.
Confirm your buffer is compatible with your specific assay or enzyme
Some buffers interfere with specific assays: Tris can interfere with certain metal-chelation or ninhydrin-based assays; phosphate buffers precipitate divalent metal ions like Ca2+ and Mg2+; and carbonate buffers absorb CO2 from air. Checking buffer compatibility with the specific enzymes or detection reagents in your assay avoids unexpected interference.
Choose between powder, concentrated liquid, and ready-to-use formats
Buffer powders require weighing, dissolving, and pH adjustment; concentrated liquid stocks (typically 10X) require dilution and pH verification; and ready-to-use solutions at working concentration are the most convenient but highest-cost-per-volume format. The best choice depends on your lab's consumption rate and time constraints.
Confirm whether your buffer needs to be sterile for cell culture use
Buffers used in cell culture applications, including cell washing and dilution in PBS or HEPES, require sterile-filtered or autoclavable formulations to prevent contaminating cultures. Pre-made sterile PBS and HEPES buffer solutions are the standard choice for routine cell culture use.
Store concentrated buffer stocks appropriately to prevent microbial growth
Prepared buffer solutions without antimicrobial preservatives are susceptible to microbial growth on storage, particularly at room temperature. Storing working buffer solutions at 4&deg;C and using sterile preparation or filtration for solutions stored beyond a few days reduces this risk.
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<h2>Specifications context</h2>
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Tris buffer has a notable temperature coefficient of approximately -0.031 pH units per degree Celsius, meaning a Tris buffer titrated to pH 8.0 at room temperature will measure approximately pH 7.7 at 37&deg;C, a shift large enough to affect pH-sensitive applications if not accounted for during preparation. As of 2026, sterile, ready-to-use PBS and HEPES buffer solutions remain among the highest-volume biochemical reagent purchases in molecular and cell biology labs, driven by universal utility and the convenience of preparation-free use.
<a href="https://mbpinc.net/contact-us">Contact the helpful team at MBP</a> today to request a quote for your specific research requirements.

Buffers & Solutions

Molecular Depot

Key Specifications

Poly(ethylene glycol) methyl ether 500 (PEG 500 MME)

Poly(ethylene glycol) methyl ether 500 (PEG 500 MME) by Molecular Depot is a highly pure polymer of ethylene glycol with one methyl ether group (PEG 500 MME). Low molecular weight PEG MMEs are liquids. It is used as a precipitant in protein crystallization screens and as a solvent and polymer building block. Each unit contains 10 mL. MBP supplies Molecular Depot buffer reagents to research labs in the United States, Canada and worldwide.