Almost all studies using blood as primary cell source required blood samples in an average range of 10 mL. Two publications described the use of smaller amounts of peripheral blood (2–6 mL) for the purification of enough CD34+ cells for further successful reprogramming [58, 59]. An even better solution is the generation of iPSCs from human finger-prick blood. In a recently published paper, the authors could prove that the volume of a single blood drop is sufficient for the isolation of enough cells for successful reprogramming [60]. They could even show that this single-drop volume (10 μL) is sufficient for reprogramming, DNA sequencing, and blood serotyping in parallel. This easy and barely invasive method to get somatic cells for reprogramming is not only uncomplicated for the patients, as they can even sting their fingers themselves, but also comes along with a high reprogramming efficiency (100–600 colonies per mL of finger-tip capillary blood). The development of international iPSC banks can be facilitated by this protocol.
