Chlortetracycline, a fluorescent probe for pH of calcium stores in cells

Jose Jacob, Deepthi Chandran, Ranjana Sasidharan, Leena Kuruvila, U. K. Madhusudan, Nivedita L. Rao, Dibyajyoti Banerjee

Research output: Contribution to journalArticle

3 Citations (Scopus)


Endoplasmic reticulum is the major storage site for Ca2+ that is mobilized during activation of cell functions. Chlortetracycline (CTC) loaded into calcium stores of fresh, isolated human blood lymphocytes was found to be sensitive to changes in H+ concentration, in addition to its established sensitivity to Ca2+. Determination of pH of calcium stores was based on dissociation of fluorescent CTC·Ca2+ with decrease in pH. Concentrations of H+ at the calcium stores were calibrated to different levels by equilibrating it with different extracellular pH buffers using the H+ ionophore, nigericin. It was possible to determine the pH of two pools of calcium stores; they were 7.2 and 6.2.

Original languageEnglish
Pages (from-to)671-674
Number of pages4
JournalCurrent Science
Issue number5
Publication statusPublished - 10-03-2003
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Agricultural and Biological Sciences(all)
  • General

Cite this

Jacob, J., Chandran, D., Sasidharan, R., Kuruvila, L., Madhusudan, U. K., Rao, N. L., & Banerjee, D. (2003). Chlortetracycline, a fluorescent probe for pH of calcium stores in cells. Current Science, 84(5), 671-674.