Measurements of Intracellular Free Ca++

  • Antonio Scarpa
  • George Dubyak
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 151)


This manuscript reviews the work of this laboratory over the last six years in measuring, non-destructively and kinetically, ionized Ca++ in the cytosol of single resting cells and the changes in Ca++ following metabolic, electrical, and contractile events. The strategy of this study is to use Ca++ indicators with suitable selectivity and sensitivity, to inject them into the cytosol of large cells, and to measure with sensitive micro-spectrophotometry the absorbance of these indicators in situ as a function of Ca++ concentration. This approach, which essentially uses a large cell as a biological cuvet, has been successful both in large neurons and single large muscle cells. We will briefly review five areas: the characteristics of Ca++ metallochromic indicators; the experimental set-up to measure free cytosolic Ca++ in single cells; the measurement of free Ca++ in a resting cell; the kinetics of mitochondrial Ca++ uptake and release in single cells in situ; and the intracellular free Ca++ transients during contractile events in a single muscle cell.


Dual Wavelength Contractile Event Squid Giant Axon Squid Axon Wavelength Pair 
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Copyright information

© Plenum Press, New York 1982

Authors and Affiliations

  • Antonio Scarpa
    • 1
  • George Dubyak
    • 1
  1. 1.Department of Biochemistry and BiophysicsUniversity of Pennsylvania School of MedicinePhiladelphiaUSA

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