CAPSO

CAPSO is a useful secondary standard buffer. The second dissociation constant pK2 value of CAPSO has been measured and the useful pH range for CAPSO is 8.9 - 10.3. It is a biological and zwitterionic buffer commonly categorized as a Good's buffer. CAPSO has many applications some of which include immunoblotting and westerns. Additionally, CAPSO is used in the electrotransfer of proteins to PVDF or nitrocellulose membranes. CAPSO buffer has very low metal-binding constants and is, therefore, particularly suited to investigate metal-dependent enzymes. CAPSO is a very water-soluble buffering reagent with an optimum buffering pH of 10.4 and minimal reactivity with enzymes or proteins with minimal salt effects.

white powder

CAPSO was used as biological buffer in the following studies:
To maintain pH 9 during water leach test for the analysis of high-carbon coal fly ash-soil mixtures.
Chemiluminescent in situ hybridization using soybean peroxidase-labeled peptide nucleic acid (PNA) probes.
Preparation of planar bilayer lipid membranes.
It may be employed as buffer for the electrophoretic analyses in non-denaturing gels, to investigate macromolecular self-association of ADP-ribosyltransferase protein in solution.

Add sodium sulfite (25.20 g, 0.2 mol) and sodium bisulfite (64.48 g, 0.62 mol) to the three-mouth flask. Heat to dissolve the reactants in water and slowly add epichlorohydrin (50.08 g, 0.54 mol) to the bottle. After vigorous stirring at 30 °C for 2 h, the mixture is cooled in an ice bath. CAPSO is obtained by vacuum suction, drying, and recrystallization.

CAPSO is a useful secondary standard buffer. Second dissociation constant pK₂ value of CAPSO has been measured. Useful pH range for CAPSO is 8.9 - 10.3.