Table 1.

Comparison of nonconfocal, confocal, and multiphoton fluorescence scanning microscopy for in vivo sensing of DiIC18(3)-labeled RBCs

Parameter measuredNonconfocalConfocalMultiphoton
Output power, mW* 1135
Background intensity, a.u.492–65147–10815–47
Signal intensity, a.u.786–3,895337–1,588204–3,895
S/B ratio1.30–6.983.46–21.905.51–108.90
S/B mean2.36 ± 0.96 9.37 ± 4.37 22.38 ± 14.52
Number detected, cells/min 124.0 ± 13.2 54.8 ± 8.8 100.0 ± 11.1
  • S/B, signal-to-background ratio.

  • *Output power was measured as the laser power out of objective lens.

  • Values are expressed ± SD.

  • Number detected represents the number of cells detected by two-photon fluorescence microscopy.