Polyethylene glycol 8000 / PEG8000

Chemical formula: HO(CH₂CH₂O)nH

Solubility: H2O: 50 mg/mL, clear, colorless

Polyethylene glycol 8000/PEG8000 products are non-toxic, non-irritating, have good water solubility, and have good compatibility with many organic components. They have excellent lubricity, moisture retention, dispersion, adhesive, antistatic agent and softener.

Action mechanism

Solubilization and stabilization

High water solubility: Through the polar group of the molecular chain (hydroxyl) to form hydrogen bonds with water, significantly improve the solubility of fat-soluble components (such as certain organic substrates, antibody markers) in the water phase.

Prevent precipitation: reduce the viscosity of the system and inhibit the precipitation of components to maintain the uniformity of the detection system (such as the stability of chemiluminescent substrates or nucleic acid probes).

Lubrication and antistatic

Reduce friction: It plays a lubricating role in microfluidic chips, pipette suction and other instruments to reduce liquid flow resistance.

Antistatic adsorption: reduce the accumulation of charge on the surface of the instrument to avoid the loss of samples or reagents due to electrostatic adsorption.

Adjust viscosity and slow release function

Control of reaction rate: High concentration of PEG8000 can prolong the reagent diffusion time, which is used to optimize the dynamic balance of enzymatic reaction or molecular hybridization.

Slow-release carrier: As a slow-release carrier for drugs or probes to extend the response time of detection signals.

Application scenario

immunoassay

ELISA/ chemiluminescence: Used as diluent or blocking solution component to improve the uniform distribution and stability of antibodies/antigens.

Latex agglutination test: enhance the coating efficiency of latex particles on target antigens and reduce non-specific binding.

Molecular diagnosis

PCR/qPCR: As an additive to the PCR reaction system, it inhibits the formation of nucleic acid secondary structure and improves the amplification efficiency.

LAMP/CRISPR: modulates reaction viscosity and stabilizes Cas proteins or prime-template complexes.

Microfluidic and POCT

Chip lubrication: Reduce bubble formation and liquid retention in microchannels to increase detection flux.

Strip coating: Improve the diffusion rate of liquid on the fiber film, shorten the detection time.

Biochemical detection

Enzyme-label plate pretreatment: reduces surface tension, promotes enzyme-label antibody adsorption and reduces background noise.

Usage amount

Immunoassay: 0.1-1% (ELISA diluent/blocking solution).

Molecular diagnosis: 0.5%-3% (PCR reaction system).

Microfluidic chip: 0.01%-0.1% (lubricant).

Slow release system: 5%-10% (need to be adjusted according to the target molecular release rate).

Dissolution method

Heating dissolution: heating to more than 60 ° C to accelerate dissolution, after cooling to restore viscosity characteristics.

Gradient addition: Avoid sudden changes caused by one-time addition of high concentration PEG8000.

Matters needing attention

Sealed and stored in dry environment (15-25 ° C recommended) to avoid moisture agglomeration or high temperature degradation.

Slight delamination may occur in long-term storage. Shake well before use.

Temperature sensitivity: High temperatures (>80 ° C) may lead to molecular chain breakage or loss of solubilization ability.

pH compatibility: Stable in the range of pH 4-10, easy to hydrolysis failure under strong acidic/alkaline conditions.

Plastic containers: long-term contact may swell polyethylene (PE) or polypropylene (PP) containers, it is recommended to use short-term or use glass/stainless steel containers.

Protein interference: Excess may be adsorbed to antibodies or antigens, and the concentration needs to be optimized through pre-experiments.

Ionic surfactant: Combination with strong ionic reagents such as SDS may lead to precipitation.

Hydrophobic substances: It is necessary to verify whether the solubilization effect of the target molecule meets the demand.

Q&A

Q: Why is PEG8000 often used in PCR reactions?

A: Its slow-release effect can inhibit the non-specific amplification of DNA polymerase, while stabilizing the viscosity of the reaction system and reducing bubble interference.

Q: How to deal with solution turbidity after PEG8000 use?

A: It may be that the concentration is too high or interacts with other ingredients, and the concentration needs to be reduced or the compatible reagent needs to be replaced.

Q: Can it directly replace Triton X-100 for cell permeability?

A: Not recommended, because PEG8000 has no membrane breaking function and is mainly used for solubilization and lubrication, rather than destroying cell structure.

Q: What if the flow speed slows down after PEG8000 is added to the microfluidic chip?

A: Need to optimize the concentration (<0.1%) or switch to low molecular weight PEG (such as PEG400).

Q: Does PEG8000 affect the chemiluminescence signal intensity?

A: There is no significant effect at a reasonable concentration, but excessive amounts may adsorb luminescent substances, and the optimal addition amount needs to be determined through experiments.