Table 1.
Comparison of nonconfocal, confocal, and multiphoton fluorescence scanning microscopy for in vivo sensing of DiIC18(3)-labeled RBCs
| Parameter measured | Nonconfocal | Confocal | Multiphoton |
|---|---|---|---|
| Output power, mW* | 1 | 1 | 35 |
| Background intensity, a.u. | 492–651 | 47–108 | 15–47 |
| Signal intensity, a.u. | 786–3,895 | 337–1,588 | 204–3,895 |
| S/B ratio | 1.30–6.98 | 3.46–21.90 | 5.51–108.90 |
| S/B mean | 2.36 ± 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.