Here, the limb of a Scleraxis-GFP mouse embryo is imaged by confocal microscopy. Scleraxis-GFP is a recently discovered, fluorescently labeled transcription factor that is exclusively expressed in tendon cells. In mice, muscles (red), tendons (green), and nerves (blue) of the limbs are largely established by ~14.5 days after fertilization. In humans, this occurs after ~9 weeks of embryogenesis.
By A. Kelsey Lewis, Gabrielle Kardon, Yong Wan (University of Utah) and Ronen Schweitzer (Oregon Health and Science University)
A pollen sac opens on the “four o’clock flower” (Mirabilis jalapa). The image was recorded with a confocal microscope at magnification 100x, field width: 840 μm. Autofluorescence of the sample was recorded in 3 different channels (RGB, dye settings: DAPI [405nm], Acridine Orange [488nm] and Alexa Fluor 546 [543nm]).