Simplified equation to extract diffusion coefficients from confocal FRAP data

Minchul Kang, Charles A. Day, Anne K. Kenworthy, Emmanuele DiBenedetto

Research output: Contribution to journalArticlepeer-review

107 Scopus citations


Quantitative measurements of diffusion can provide important information about how proteins and lipids interact with their environment within the cell and the effective size of the diffusing species. Confocal fluorescence recovery after photobleaching (FRAP) is one of the most widely accessible approaches to measure protein and lipid diffusion in living cells. However, straightforward approaches to quantify confocal FRAP measurements in terms of absolute diffusion coefficients are currently lacking. Here, we report a simplified equation that can be used to extract diffusion coefficients from confocal FRAP data using the half time of recovery and effective bleach radius for a circular bleach region, and validate this equation for a series of fluorescently labeled soluble and membrane-bound proteins and lipids. We show that using this approach, diffusion coefficients ranging over three orders of magnitude can be obtained from confocal FRAP measurements performed under standard imaging conditions, highlighting its broad applicability.

Original languageEnglish (US)
Pages (from-to)1589-1600
Number of pages12
Issue number12
StatePublished - Dec 2012
Externally publishedYes


  • Confocal laser scanning microscope
  • Diffusion coefficient
  • FRAP
  • Fluorescence microscopy
  • Half time of recovery


Dive into the research topics of 'Simplified equation to extract diffusion coefficients from confocal FRAP data'. Together they form a unique fingerprint.

Cite this