Fig. 1.

Experimental setup of SE-ADM system and observation of cultured melanoma cells. A) A schematic diagram of the SE-ADM system based on high resolution FE-SEM. The liquid-sample holder containing cultured cells was mounted on the stage attached to the pre-amplifier, which was introduced into the SEM specimen chamber. The scanning EB was applied to the W-coated SiN film at a low acceleration voltage. The measurement terminal under the holder detected the electrical signal through the liquid specimens. B) Overview of the liquid-sample holder with cultured melanoma cells. MNT-1 cells were on the upper SiN film and the W-coated side was irradiated with the scanning EB. C) A conceptual diagram of melanosomes in a cell. D) A low magnification SE-ADM image of living MNT-1 cells 7 days after the culture in medium (1000 ×) with a 6-kV EB and − 9 V bias. E) An SE-ADM image of MNT-1 cells (2500 ×) in the red rectangle in (D). F) A high magnification image of MNT-1 cells (10,000 ×). G) A higher magnification image (20,000 ×) of melanosomes in the red rectangle in (F). Scale bars, 10 µm in (D), 5 µm in (E), 1 µm in (F) and 500 nm in (G).