Jo Younggeun, Shen Fengshan, Hahn Young Ki, Park Ji-Ho, Park Je-Kyun
Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea.
Samsung Electronics, 4 Seocho-daero 74-gil, Seocho-gu, Seoul 06620, Republic of Korea.
Micromachines (Basel). 2016 Mar 30;7(4):56. doi: 10.3390/mi7040056.
Droplet microfluidics is a promising tool for single-cell analysis since single cell can be comparted inside a tiny volume. However, droplet encapsulation of single cells still remains a challenging issue due to the low ratio of droplets containing single cells. Here, we introduce a simple and robust single cell sorting platform based on a magnetophoretic method using monodisperse magnetic nanoparticles (MNPs) and droplet microfluidics with >94% purity. There is an approximately equal amount of MNPs in the same-sized droplet, which has the same magnetic force under the magnetic field. However, the droplets containing single cells have a reduced number of MNPs, as much as the volume of the cell inside the droplet, resulting in a low magnetic force. Based on this simple principle, this platform enables the separation of single cell-encapsulated droplets from the droplets with no cells. Additionally, this device uses only a permanent magnet without any complex additional apparatus; hence, this new platform can be integrated into a single cell analysis system considering its effectiveness and convenience.
微滴微流控技术是一种很有前景的单细胞分析工具，因为单个细胞可以被分隔在微小的体积内。然而，由于含有单细胞的微滴比例较低，单细胞的微滴封装仍然是一个具有挑战性的问题。在此，我们基于一种磁泳方法，引入了一个简单且稳健的单细胞分选平台，该方法使用单分散磁性纳米颗粒（MNPs）以及纯度大于94%的微滴微流控技术。在相同大小的微滴中，MNPs的数量大致相等，在磁场作用下具有相同的磁力。然而，含有单细胞的微滴中MNPs的数量会减少，减少的量与微滴内细胞的体积相同，从而导致磁力降低。基于这个简单的原理，该平台能够将封装有单细胞的微滴与不含细胞的微滴分离。此外，该装置仅使用一块永久磁铁，无需任何复杂的附加设备；因此，考虑到其有效性和便利性，这个新平台可以集成到单细胞分析系统中。
