WHAT IT IS
Biocompatibility in liquid chromatography (LC) refers to the use of materials and flow paths that do not react with, adsorb, or degrade sensitive biological samples. Conventional LC systems often contain stainless steel in pumps, valves, and tubing. While suitable for many small-molecule analyses, these surfaces can interact with proteins, peptides, nucleic acids, and other biomolecules, leading to adsorption, denaturation, or metal-catalyzed degradation.
Biocompatible LC systems use inert materials such as titanium, PEEK (polyether ether ketone), ceramics, or specialized coatings to minimize sample loss and preserve analyte integrity. This design is particularly important in proteomics, metabolomics, biopharmaceutical testing, and other applications involving fragile or labile biomolecules.
HOW IT WORKS
Biocompatibility is achieved by modifying fluidic components that come into direct contact with the sample:
Material Choice - Inert materials (titanium, PEEK, ceramics) replace stainless steel in pumps, valves, and tubing.
Flow Path Design - Internal surfaces are polished or coated to reduce sites where proteins and peptides might adsorb.
Specialized Fittings - Inert valves, seals, and check valves minimize reactivity and sample loss.
Column Adaptation - Columns packed in PEEK housings or lined with inert coatings prevent analyte–metal interactions.
Detector Compatibility - Flow cells in UV, fluorescence, or MS detectors are made from inert materials to avoid adsorption.
The result is a flow path where proteins, peptides, nucleic acids, and other sensitive analytes move through the system without significant degradation or loss.
ADVANTAGES
Improved Recovery: Prevents sample loss caused by biomolecules sticking to metal surfaces.
Analyte Stability: Reduces oxidation, denaturation, or metal-induced degradation.
Better Reproducibility: Minimizes variability in peak areas and shapes for complex biomolecules.
Expanded Applicability: Enables reliable analysis of proteins, peptides, oligonucleotides, and other fragile analytes.
Compatibility with Bio-LC Columns: Works seamlessly with size-exclusion, ion-exchange, and affinity columns designed for biomolecules.
APPLICATION AREAS
Proteomics: High-sensitivity analysis of proteins and peptides.
Biopharmaceuticals: Characterization of monoclonal antibodies, therapeutic proteins, and oligonucleotide drugs.
Metabolomics: Analysis of metabolites prone to degradation or adsorption.
Nucleic Acid Studies: Separation of DNA, RNA, and oligonucleotides.
Clinical LC: Measurement of biological fluids (plasma, serum, urine) with minimal analyte loss.
CHALLENGES AND LIMITATIONS
Higher Cost: Biocompatible pumps, valves, and columns are more expensive than standard components.
Lower Pressure Tolerance: Materials like PEEK cannot withstand the very high pressures used in UHPLC.
Durability: Some inert polymers wear faster than stainless steel under routine use.
Solvent Restrictions: Strong acids, bases, or aggressive organic solvents may damage polymer components.
System Complexity: Maintaining a fully biocompatible flow path requires careful attention to fittings, connections, and column choice.