Enzyme Assays: Provides a 100 mM citrate buffer at pH 4.0 for acid-optimized enzymes (e.g., acid phosphatases, aspartic proteases, glycosidases).

Protein Purification: Used as a low-pH buffer for cation-exchange workflows and gentle elution conditions.

Immunoaffinity Purification: Enables mild, low-pH elution of IgG from Protein A/G resins while maintaining buffer capacity.

ELISA/HRP Substrate Buffer: Serves as a 100 mM citrate buffer for peroxidase substrate reactions (e.g., OPD/TMB) requiring acidic pH.

Bioprocess pH-Shift Steps: Used for low-pH holds, viral inactivation steps, and pH conditioning in downstream processing.

Formulation and Storage: Provides chelating, acidic conditions to limit metal-catalyzed oxidation and stabilize acid-stable proteins/peptides.

Microbiology: Supports acid-tolerance and survival assays for organisms such as Lactobacillus and Salmonella.

Histology/IHC: Applied in low-pH antigen retrieval protocols for select epitopes requiring acidic conditions.