Microfluidic systems have been widely utilized in high-throughput biology analysis, but the difficulties in liquid manipulation and cell cultivation limit its application. This work has developed a new digital microfluidic (DMF) system for on-demand droplet control. By adopting an extending-depth-of-field (EDoF) phase modulator to the optical system, the entire depth of the microfluidic channel can be covered in one image without any refocusing process, ensuring that 95% of the particles in the droplet are captured within three shots together with shaking processes. With this system, suspension droplets are generated and droplets containing only one yeast cell can be recognized, then each single cell is cultured in the array of the chip. By observing their growth in cell numbers and the green fluorescence protein (GFP) production via fluorescence imaging, the single cell with the highest production can be identified. The results have proved the heterogeneity of yeast cells, and showed that the combined system can be applied for rapid single-cell sorting, cultivation, and analysis.

膨胀超分辨技术是近几年出现的一种对样品制备进行改进实现分辨率提升的超分辨技术，由于其与其他光学技术的兼容性强，可以进一步提高分辨率，引起了越来越多研究人员的关注。复合膨胀技术是膨胀超分辨技术改进的一个主要发展方向之一，膨胀结合光学波动超分辨技术（ExM‐SOFI）在复合膨胀技术中是一种受限较小且使用较为广泛的技术。为了增强现有ExM‐SOFI技术的成像效果，本课题组将成像缓冲液技术应用于ExM‐SOFI技术，以增强膨胀样品在拍摄过程中的抗淬灭能力，从而使普通染料在ExM‐SOFI中的荧光强度、荧光波动幅度和闪烁比等均有增强。微管和囊泡的染色成像结果表明，使用这种技术可以使样品在高阶SOFI中保持真实结构，伪影更少，因而高阶SOFI技术可以提升膨胀样品的最终分辨率。

The endogenous fluorophores such as reduced nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) and flavin adenine dinucleotide (FAD) in cells and tissues can be imaged by fluorescence lifetime imaging microscopy (FLIM) to show the tissue morphology features, as well as the biomolecular changes in microenvironment. The two important coenzymes in cellular metabolism, NAD(P)H and FAD, can be used to monitor the cellular metabolic status. This work proposed a novel method to study the uterine metabolism at the adjacent site of healthy cervix. It was found that the benign uterine tumors such as leiomyomas and adenomyosis with abnormal cell growth can be detected by measuring the fluorescence lifetime of NAD(P)H and FAD in adjacent healthy cervical tissues. This method opened a novel strategy for afflicted women to undergo the cervical biopsies instead of hysterectomies for detecting tumors, which can preserve the fertility of patients. The FLIM studying on NAD(P)H and FAD indicated the correlation between metabolism and some diseases, including diabetes, hyperthyroidism and obesity. It was also suggested that the metabolic level might be quite different for a patient with a malignant tumor history.

Hydrophilic photo luminescent semiconductor quantum dots (QDs) are novel nanometer-size probes, which may have potential using in bio-imaging for biological objects. In this work, the photo-stability of these QDs in two kinds of living cells was studied, compared with conventional biological probes such as fluorescein isothiocyanate (FITC) and green fluorescence protein (GFP). It was found that the concentration of QDs in living cells is the dominant factor for its photo-stability in biological environment. When the concentration of the intracellular QDs was high, the QDs show good photo-stability that is much better than the organic fluorescent probes. However when its concentration was low, the QDs also can be photo-bleached quickly. Thus the reaching of the certain concentration level is the critical condition for QDs in the application of bio-imaging.