Intracellular labeling method for chip-based capillary electrophoresis fluorimetric single cell analysis using liposomes

• Published in: Journal of Chromatography A Vol. 1135; no. 1; pp. 109 - 114
• Main Authors: Sun, Yue, Lu, Min, Yin, Xue-Feng, Gong, Xing-Guo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 24.11.2006; Elsevier
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical, structural and metabolic biochemistry; Biological and medical sciences; Cells - chemistry; Cells - metabolism; Cells - ultrastructure; Chip-based CE; Electrophoresis, Capillary - methods; Fluorescence; Fluorescent Dyes - chemistry; Fluorometry - methods; Fundamental and applied biological sciences. Psychology; Intracellular derivatization; Lasers; LIF; Liposomes; Liposomes - chemistry; Reproducibility of Results; Sensitivity and Specificity; Single cell analysis; Staining and Labeling; LIF; Liposomes; Chip-based CE; Single cell analysis; Intracellular derivatization; Encapsulation; Liver; Confocal microscopy; Derivatization; Scanning microscope; Hepatocyte; Tumor cell; Human; Fluorescence detector; Capillary electrophoresis; Laser induced fluorescence; Liposome; System on a chip; Cell line; Analysis method; Fluorescent labelling; Intracellular; Miniaturization; Microfluidics; Fluorescence microscopy; Confocal laser scanning microscopy
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2006.09.020

An intracellular derivatization method mediated by liposome was developed for single cell analysis with chip-based capillary electrophoresis (CE) and laser-induced fluorescence (LIF) detection. Liposomes with an average diameter of 100 nm were produced from phosphatidylcholine to encapsulate fluorescent dyes by an ultrasonic method. The encapsulation yield and the vesicle density were determined to be 46 ± 5% and 8.8 × 10 14/mL, respectively. The amount of fluorescent dye that entered the cells was dependent on the duration of incubating cells with liposomes, liposome density, and concentration of the dye solution encapsulated in liposomes. The described method introduced cell membrane nonpermeable fluorescent dyes into living cells without reducing cell viability. Single cell analysis using microfluidic chip-based CE revealed that liposome-membrane fusion occurred after entrance of liposomes into the cells, with release of encapsulated fluorescence dyes and labeling of intracellular species.