Premium
Fluorescence Dynamics in the Endoplasmic Reticulum of a Live Cell: Time‐Resolved Confocal Microscopy
Author(s) -
Ghosh Shirsendu,
Nandi Somen,
Ghosh Catherine,
Bhattacharyya Kankan
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201600425
Subject(s) - confocal , fluorescence , endoplasmic reticulum , organelle , a549 cell , fluorescence microscope , confocal microscopy , live cell imaging , chemistry , biophysics , cancer cell , cell , lung cancer , microscopy , biology , cancer , microbiology and biotechnology , pathology , biochemistry , optics , medicine , physics , genetics
Fluorescence dynamics in the endoplasmic reticulum (ER) of a live non‐cancer lung cell (WI38) and a lung cancer cell (A549) are studied by using time‐resolved confocal microscopy. To selectively study the organelle, ER, we have used an ER‐Tracker dye. From the emission maximum ( λ max em ) of the ER‐Tracker dye, polarity (i.e. dielectric constant, ϵ ) in the ER region of the cells (≈500 nm in WI38 and ≈510 nm in A549) is estimated to be similar to that of chloroform ( λ max em =506 nm, ϵ ≈5). The red shift by 10 nm in λ max em in the cancer cell (A549) suggests a slightly higher polarity compared to the non‐cancer cell (WI38). The fluorescence intensity of the ER‐Tracker dye exhibits prolonged intermittent oscillations on a timescale of 2–6 seconds for the cancer cell (A549). For the non‐cancer cell (WI38), such fluorescence oscillations are much less prominent. The marked fluorescence intensity oscillations in the cancer cell are attributed to enhanced calcium oscillations. The average solvent relaxation time (< τ s >) of the ER region in the lung cancer cell (A549, 250±50 ps) is about four times faster than that in the non‐cancer cell (WI38, 1000±50 ps).