title: Error analysis of ratiometric imaging of extracellular pH in a window chamber model.
abstract: Ratiometric fluorescence-imaging technique is commonly used to measure extracellular pH in tumors and surrounding tissue within a dorsal skin-fold window chamber. Using a pH-sensitive fluorophore such as carboxy SNARF-1 one can measure pH distributions with high precision. However, it is often observed that the measured pH is lower than expected, with a bias that varies from one image to another. A comprehensive analysis of possible error sources is presented. These error sources include photon noise, estimator bias, instrument errors, temperature, and calibration errors from biological factors.
authors.affiliation: University of Arizona, College of Optical Sciences, 1630 East University Boulevard, Tuscon, Arizona 85721, USA.
authors.forename: Yuxiang
authors.initials: Y
authors.lastname: Lin
authors.forename: Tzu-Yu
authors.initials: TY
authors.lastname: Wu
authors.forename: Arthur F
authors.initials: AF
authors.lastname: Gmitro
mesh_terms: D000818:Animals; D001578:Benzopyrans / Q000032:analysis / Q000737:chemistry; D002138:Calibration; D045744:Cell Line, Tumor; D060833:Cellular Microenvironment / Q000502:physiology*; D005110:Extracellular Space / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods*; D009284:Naphthols / Q000032:analysis / Q000737:chemistry; D009374:Neoplasms, Experimental / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016012:Poisson Distribution; D012235:Rhodamines / Q000032:analysis / Q000737:chemistry; D012884:Skin Window Technique / Q000379:methods*
chemical_list: D001578:Benzopyrans; D005456:Fluorescent Dyes; D009284:Naphthols; D012235:Rhodamines; C091666:seminaphthorhodaminefluoride; D049452:Green Fluorescent Proteins