•Average Molecular Weight: 18,000

•HLB: >24

•Targets: Enzymes, antibodies, antigens, fluorescent markers, etc.

•Mechanism:

•Forms micelles (low critical micelle concentration, ~0.001–0.01%) to encapsulate hydrophobic regions, reducing protein denaturation.

•Mitigates interfacial stress damage during lyophilization/reconstitution (synergizes with sugar-based protectants like trehalose).

•Applications:

•ELISA Reagents: Protects horseradish peroxidase (HRP) activity, preventing inactivation from freeze-thaw cycles.

•Chemiluminescence Reagents: Stabilizes luminescent markers (e.g., acridinium esters), reducing background signals.

•Targets: Lipoproteins, cell debris, fibrinogen in serum/plasma.

•Mechanism:

•Hydrophobic PPO chains adsorb lipids, forming micelles to "trap" them and avoid non-specific binding with detection antibodies.

•PEO chains create a hydrophilic barrier, blocking protein adsorption on hydrophobic surfaces (e.g., microplates, magnetic beads).

•Typical Formulations:

•Immunoturbidimetric Reagents: 0.05–0.2% Tetronic 1307 + 0.1% signal enhancer BAP-1 to disperse chylomicrons in lipemic samples.

•Nucleic Acid Extraction Reagents: Utilizes weak cationic properties to bind impurity proteins, improving DNA purity.

•Targets: Gold nanoparticles (AuNPs), quantum dots, magnetic beads.

•Mechanism:

•PPO chains adsorb onto nanoparticle surfaces, while PEO chains extend outward to provide steric stabilization.

•Star-shaped structure enhances steric repulsion, preventing particle aggregation (superior to linear surfactants like Tween-20).

•Application Examples:

•Lateral Flow Strips: 0.01–0.05% Tetronic 1307 disperses gold-labeled antibodies, improving color uniformity on test lines.

•Homogeneous Immunoassays: Stabilizes fluorescent magnetic microspheres, reducing sedimentation.

•Function: Prevents inactivation of active ingredients during lyophilization and accelerates reconstitution.

•Mechanism:

•Forms a glassy matrix to minimize ice crystal-induced damage to protein structures.

•Facilitates rapid dispersion and reduces interfacial tension during reconstitution.

•Example Formulation:

•Lyophilized PCR Enzyme Mix: 1% trehalose + 0.1% Tetronic 1307 + 0.05% signal enhancer BAP-1.

Pluracare® and Tetronic® are trademarks of BASF.

•General Application: 0.01% - 0.2% (w/v). Concentrations exceeding this range may lead to increased viscosity or interference with detection signals.

•Avoid direct mixing with strong ionic surfactants (e.g., SDS), as this may disrupt the micelle structure.

•In systems containing high salt concentrations (e.g., >0.5M NaCl), it is necessary to increase the concentration of Tetronic 1307 to maintain dispersing capability.