Immunoaffinity Microchip for Hematopoietic Stem Cell Enrichment From Human Blood

Stem cells have been a focus of research due to their great promise to develop new treatments for human disease. Hematopoietic stem cells (HSCs) are adult stem cells found in bone marrow that give rise to all the blood cell types. Significant progress has been achieved in identification and enrichment of HSCs in recent years. For example, CD34 and other lineage markers have been discovered that identify HSCs in blood and techniques such as fluorescent-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS), have been developed to enrich HSCs for blood transplantation. However, current enrichment techniques have limitations such as low throughput, poor reproducibility in purity or yield. Here we propose an immunoaffinity based microchip with specific antibody coated on its surface to enrich HSCs with high performance. CD34, a trans-membrane protein expressed on HSCs but lost upon their differentiation to mature blood cells, is used as the bio-marker for HSCs. Anti-CD34 antibody was immobilized on the surface of the microchip for HSC enrichment with high purity. A micrpost design was introduced to maximize the surface area of the device to obtain high throughput enrichment.