Being easy, safe and reliable, non-invasive prenatal diagnosis (NIPD) has been greatly pursued in recent years. Holding the complete genetic information of the fetus, fetal nucleated red blood cells (fNRBCs) are viewed as a suitable target for NIPD application. However, effective separating fNRBCs from maternal peripheral blood for clinic use still faces great challenges, given that fNRBCs are extremely rare in maternal blood circulation. Here, by combining the high-throughput inertial microfluidic chip with multifunctional microspheres as size amplification, we develop a novel method to isolate fNRBCs with high performance. To enlarge the size difference between fNRBCs and normal blood cells, we use the gelatin coated microspheres to capture fNRBCs with anti-CD147 as specific recognizer at first. The size difference between fNRBCs captured by the microspheres and normal blood cells makes it easy to purify the captured fNRBCs through the spiral microfluidic chip. Finally, the purified fNRBCs are mildly released from the microspheres by enzymatically degrading the gelatin coating. Cell capture efficiency about 81%, high purity of 83%, as well as cell release viability over 80% were achieved using spiked samples by this approach. Additionally, fNRBCs were successfully detected from peripheral blood of pregnant women with an average of 24 fNRBCs per mL, suggesting the great potential of this method for clinical non-invasive prenatal diagnosis.

无创产前诊断（NIPD）以其简单、安全、可靠的特点，近年来受到人们的大力追捧。胎儿有核红细胞（fNRBC）保存着胎儿的完整遗传信息，被视为 NIPD 应用的合适目标。然而，由于fNRBCs在母体血液循环中极为罕见，从母体外周血中有效分离fNRBCs用于临床仍面临巨大挑战。在这里，通过将高通量惯性微流控芯片与作为尺寸放大的多功能微球相结合，我们开发了一种高性能分离 fNRBC 的新方法。为了扩大fNRBC与正常血细胞之间的大小差异，我们首先使用明胶包被的微球以抗CD147作为特异性识别器捕获fNRBC。微球捕获的fNRBC与正常血细胞之间的尺寸差异使得通过螺旋微流控芯片可以轻松纯化捕获的fNRBC。最后，通过酶降解明胶涂层，将纯化的 fNRBC 从微球中温和释放。通过这种方法，使用加标样品实现了约 81% 的细胞捕获效率、83% 的高纯度以及超过 80% 的细胞释放活力。此外，从孕妇外周血中成功检测到fNRBCs，平均每mL 24个fNRBCs，表明该方法在临床无创产前诊断方面具有巨大潜力。