Biological Buffers


Synonym: 3-(Cyclohexylamino)-2-hydroxy-1-propanesulfonic acid, CAPSO Free Acid

CAPSO buffer is used in western and immunoblotting experiments as well as protein sequencing and identification1. Used in the electrotransfer of proteins to PVDF or nitrocellulose membranes. The high pH of this buffer makes it useful for the transfer of proteins with a pI > 8.52.
Useful pH Range 8.9 - 10.3
Working concentration range 10-50mM


        Comparison of products by grade or quality level
Name CAS Molecular Formula Mol Wt Reagent Grades Life Science Grades PharmaGrade  Solution
CAPSO 73463-39-5 C9H19NO4S 237.32





CAPSO sodium salt 102601-34-3 C9H18NO4SNa 259.30






Interaction Comments

Minimal reactivity with enzymes or proteins, minimal salt effects3.
No reported ion interaction


Literature References

  1. Wiedemeyer, R., et al. 2003. Oncogene. 22: 401-411. PMID: 12545161
  2. Szewczyk, B. and Kozloff, L.M., Anal. Biochem., v. 150, 403 (1985).
  3. Ferguson, W.J., Good, N.E., et al., Analytical Biochemistry, 104, 300-310 (1980).
  4. Ferreira CM, Pinto IS, Soares, EV, Soares HM. 2015 Royal Society of Chemistry 30989- 31003