A research group in Singapore has invented a method to generate human induced pluripotent stem cells (hiPSCs) from a single drop of blood.
This method was developed by stem cell scientists at the A*STAR Institute of Molecular and Cell Biology (IMCB). This protocol enables donors to collect their own blood samples with a single pinprick, and then send to a laboratory for further processing.
The ease of collecting such a small amount of blood and deriving hiPSCs with this new technique could potentially boost the recruitment of donors, and eventually establish large stem cell-banks that have a wide diversity of donors and represent a broad cross-section of humanity.
To derive hiPSCs from mature cells, the cells are genetically engineered to express four different genes (Oct4, Sox2, Klf4 and c-Myc). The expression of these genes drives the cells to de-differentiate and reprogram themselves into embryonic-like stem cells that can, potentially, be differentiated into any mature cell type. Besides their obvious potential for regenerative medicine, hiPSCs also can serve as excellent models to test the efficacy of particular drugs and other therapies (see here for a remarkable example). Japan, the United States, and the United Kingdom all initiatives to start hiPSC banks that make hiPSCs available for research and development.
Current protocols to derive iPSCs from human blood require respectable amounts of blood. However, the IMCB protocol only calls for single-drop volumes of blood, and produces hiPSCs at very high efficiency. IMCB has filed a patent for their protocol.
Blood samples remain stable for 48 hours and can also be grown in culture for 12 days, and this extends the finger-prick method to a wide variety of geographic regions for recruitment of donors with highly varied ethnic backgrounds, genotypes and diseases.
The integration of the IMCB technique with the hiPSC stem cell initiative paves the way for establishing a stem cell bank. This could potentially completely replace embryonic stem cells.
Yuin-Han Loh from IMCB said: “It all began when we wondered if we could reduce the volume of blood used for reprogramming. Then we tested if donors could collect their own blood sample in a normal room environment and store it. Our finger-prick technique, in fact, utilized less than a drop of finger-pricked blood. The remaining blood could even be used for DNA sequencing and othe blood tests.”
Loh and his group even showed that hiPSCs derived from a a drop of blood could be differentiated into functional heart muscle cells. This illustrated the power of biobanks around the world for hiPSC studies at a scale that was previously not possible.