title: Three dimensional multi-molecule tracking in thick samples with extended depth-of-field.
abstract: We present a non-z-scanning multi-molecule tracking system with nano-resolution in all three dimensions and extended depth of field (DOF), which based on distorted grating (DG) and double-helix point spread function (DH-PSF) combination microscopy (DDCM). The critical component in DDCM is a custom designed composite phase mask (PM) combining the functions of DG and DH-PSF. The localization precision and the effective DOF of the home-built DDCM system based on the designed PM were tested. Our experimental results show that the three-dimensional (3D) localization precision for the three diffraction orders of the grating are σ(-1st)(x, y, z) = (6.5 nm, 9.2nm, 23.4 nm), σ(0th)(x, y, z) = (3.7 nm, 2.8nm, 10.3 nm), and σ(+1s)(x, y, z) = (5.8 nm, 6.9 nm, 18.4 nm), respectively. Furthermore, the total effective DOF of the DDCM system is extended to 14 μm. Tracking experiment demonstrated that beads separated over 12 μm along the axial direction at some instants can be localized and tracked successfully.
authors.forename: Heng
authors.initials: H
authors.lastname: Li
authors.forename: Danni
authors.initials: D
authors.lastname: Chen
authors.forename: Gaixia
authors.initials: G
authors.lastname: Xu
authors.forename: Bin
authors.initials: B
authors.lastname: Yu
authors.forename: Hanben
authors.initials: H
authors.lastname: Niu