Dinish U S, Fu C Y, Chao Z X, Seah L K, Murukeshan V M, Ng B K
School of Mechanical and Aerospace Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798.
Appl Opt. 2006 Jul 10;45(20):5020-6. doi: 10.1364/ao.45.005020.
Characterization of fluorescence emissions from cells often leads to conclusive results in the early detection of cellular abnormalities. Cellular abnormalities can be characterized by their difference in the fluorescence lifetime, which may be less than nanoseconds. A sensitive frequency domain technique, also called a phase-resolved fluorescence imaging technique, is proposed in which fluorescence emissions at the same wavelengths can more effectively be separated with subnanosecond resolution in their lifetime difference. The system configuration is optimized by incorporating even-step phase shifting in the homodyne-assisted signal-processing concept along with the phase-resolved fluorescence technique to eliminate the dc offsets of emission. Experiments are carried out with simulated samples composed of two fluorescence emissions of the same wavelength but with different lifetime values. Suppression of either of the fluorescence emissions by selective imaging of the other validates the superiority of the proposed technique. Hence, this technique can potentially be applied in the early detection of cellular abnormalities.
对细胞荧光发射的表征通常能在细胞异常的早期检测中得出确定性结果。细胞异常可通过其荧光寿命的差异来表征，这种差异可能小于纳秒。本文提出了一种灵敏的频域技术，也称为相分辨荧光成像技术，在该技术中，相同波长的荧光发射能够以亚纳秒分辨率在其寿命差异上更有效地分离。通过将均匀步长相移纳入零差辅助信号处理概念以及相分辨荧光技术来优化系统配置，以消除发射的直流偏移。使用由具有相同波长但不同寿命值的两种荧光发射组成的模拟样品进行实验。通过对另一种荧光发射进行选择性成像来抑制其中任何一种荧光发射，验证了所提出技术的优越性。因此，该技术有可能应用于细胞异常的早期检测。
