In vitro labeling of actin filaments in U-2 OS
and COS-7 cells with 580CP-jasplakinolide and 610CP-jasplakinolide probes (see Scheme 4 and ref (5)). (A,B) Human osteosarcoma (U-2 OS) cells and
(C,D) kidney cells derived from the African green monkey (COS-7) were
incubated with (A,C) 580CP-jasplakinolide (5 μM
for 30 min) or (B,D) 610CP-jasplakinolide (1 μM
for 60 min) probes, respectively (followed by a washing step of additional
30 min). Live-cell STED images were acquired using a quad scanning
STED microscope (Abberior Instruments, Göttingen, Germany)
equipped with a UPlanSApo 100×/1, 40 Oil objective (Olympus,
Tokyo, Japan). (1–4) Line profiles (with a line width of 60
nm (three pixels) for averaging) were taken at locations indicated
by arrows in the enlarged sections (right). The averaged data were
fitted with a Lorentzian function and plotted. Except for contrast
stretching, no further image processing was applied. Scale bars: 5
μm (overviews), 500 nm (enlarged sections). Abbreviations: AU
(arbitrary units), Conf (confocal), FWHM (full width at half maximum),
STED (stimulated emission depletion).