Microfluidic selection and retention of a single cardiac myocyte, on-chip dye loading, cell contraction by chemical stimulation, and quantitative fluorescent analysis of intracellular calcium.
A microfluidic method to study the contraction of a single cardiac myocyte (heart muscle cell) has been developed. This method integrates various single-cell operations as well as on-chip dye loading, and quantitative analysis of intracellular calcium concentration, [Ca2+]i. After the channel enlargement by on-chip etching to accommodate large-sized cardiac myocytes, a single cell is selected and retained at a V-shaped cell retention structure within the microchip. Owing to the fragile property of the cardiac myocytes that could easily be damaged by centrifugation, the calcium-sensitive fluorescent dye was loaded in the cell by on-chip dye loading. This on-chip method minimized the damage to the cells from the use of a centrifuge in the conventional method and provided a way of cellular analysis of fragile cells. Subsequently, quantitative analysis of [Ca2+]i of a single cardiac myocyte by fluorescence measurement was achieved for the first time in a microfluidic chip, thanks to the intracellular calcium stimulant of ionomycin. The resting [Ca2+]i of the cardiomyocyte determined was consistent with the literature value. From the spontaneous contraction study, it was found that fluorescence intensity cannot represent the [Ca2+]i variation accurately, which implied the importance of the quantitative analysis of [Ca2+]i.
Li
Xiujun
X
Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6 Canada.
Li
Paul C H
PC
D000818:Animals; D002118:Calcium / Q000032:analysis*; D002469:Cell Separation / Q000379:methods*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000032:analysis; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D009200:Myocardial Contraction / Q000187:drug effects*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects*; D011817:Rabbits
D005456:Fluorescent Dyes; D007476:Ionophores; D015759:Ionomycin; D002118:Calcium