Workflow for 3D imaging in adult mouse heart
(A) Custom made imaging chamber with pinned embryonic heart for 2x lens imaging. Glass tubes border the chamber and support the glass coverslip.
(B) Imaging of the heart on an upright confocal microscope with immersion objective lens 25×; the lens is immersed in a chamber filled up with SCALE with the heart specimen pinned at the bottom.
(C) Field of view using 2x lens, allowing visualization of the entire mouse heart (postnatal day 30) without image stitching. The highlighted region was imaged also by the 10× objective to obtain a high-resolution 3D dataset of the left bundle branch. Cx40-GFP (green), tissue autofluorescence (red).
(D and E) Left ventricular lateral wall imaged with 4x dry lens for overview of the Purkinje network on Cx40-GFP mouse (D) with one region (boxed area) imaged with 25x ScaleView lens (E).
Depth of imaging could be appreciated on orthogonal views below, allowing clear distinction between subendocardial Purkinje fibers (solid bands) and more deeply located coronary artery branch (arrow) (F).