Fig. 8: Images of mucosal smear samples acquired with Pocket MUSE.

A cheek swab sample was acquired by smearing the cells on the Pocket MUSE sample holder and the same region was imaged with (a) bright-field mode and (b) MUSE fluorescent mode. The sample was collected using a conventional cotton swab, stained in 10% v/v CytoStain with 0.05% w/v propidium iodide, and washed with tap water. A close-up view of the region labeled with the box (box size: 500 × 500 µm²) is shown on the right demonstrating good image quality even near the corner of the FOV. The cytoplasm is stained in green or yellow by CytoStain. Cell nuclei (within the cytoplasm) and bacteria (outside cytoplasm) are stained in red by propidium iodide. c MUSE fluorescent images of a cotton swab tip containing a stained cheek swab sample. A close-up view of the region labeled with the box (box size: 500 × 500 µm²) is shown on the right showing cells attached to the cotton matrix without significant flattening from the glass surface due to surface tension. d MUSE fluorescent images of a cotton swab tip containing a healthy conjunctival (eyelid) swab sample stained with CytoStain and propidium iodide. The samples showed fewer cells, but more nucleic acid structures which are likely from conjunctival microorganisms. The cellulose matrices were rapidly stained in green due to the lack of viscous mucus. Scale bars: 300 µm.