Application of 4 × and 12 × 3D-ExM in visualiz ing viruses in host cells. (A) Left: schematic diagram showing the structure of EBV. GP350 is a viral envelope glycoprotein. Middle: representative 4× and 12× 3D-ExM images of EBV virions. Right: quantification of the measured and corrected diameter of EBV virions. Results are shown as the mean ± s.d. n = 44 virus particles pooled from two color-coded biological replicates. DNA was labeled with DRAQ5. (B) Left: schematic diagram showing the structure of HIV. Right: representative 12x 3D-ExM images of HIV gRNA and Gag proteins. HIV gRNA was labeled using specific FISH probes.