Enzyme Assays (Acidic pH): 0.1M Sodium Citrate, pH 5.0 provides a stable acidic buffer for assays of acid-active enzymes (e.g., glycosidases, acid phosphatases).

Protein Chromatography: Used as a buffering ion in cation-exchange and size-exclusion workflows to maintain pH 5.0 during protein binding, washing, and elution.

Immunohistochemistry (HIER): Citrate-based buffer for heat-induced epitope retrieval to unmask antigens in formalin-fixed, paraffin-embedded tissues.

Nucleic Acid Workflows: Provides mild chelation of divalent cations at pH 5.0 to help limit metal-dependent nuclease activity during DNA/RNA extraction and storage.

Anticoagulation/Calcium Chelation: Utilized in plasma and platelet processing where citrate is required to chelate Ca2+ and reduce coagulation.

Microbiology Media/Formulation: Adjusts pH and supplies citrate in culture media (e.g., citrate utilization tests distinguishing Enterobacteriaceae such as Klebsiella, Enterobacter, versus citrate-negative Escherichia coli).

Buffer Exchange and Dialysis: Employed as an equilibration and exchange buffer at pH 5.0 for desalting, concentration, and stabilization of acid-stable biomolecules.