How iPSCs are made?
We apply the integrative system: Lenti-virus delivery (LV), or a non-integrative system: Sendai-virus delivery (SV).
Lenti-virus delivery (integrated transgene)
We use a LV-delivery system, containing the OCT4, KLF4, SOX2, cMYC Yamanaka factors [15, 16]. The transgene stably integrates into the host genome and its self-silencing property assures proper differentiation capability of the generated iPSC lines.
Sendai-virus delivery (transgene-free)
The transgene-free system based on SV-delivery, where we use the commercially available (ThermoFisher) SV-reprogramming viruses [17]. Sendai-virus is an RNA based virus, remains in the cytoplasm, thus eliminating integration into the host genome. Upon reprogramming the SV backbone and transgenes clear from the cytoplasm, thus the iPSC lines become transgene-free. To confirm the transgene-free status, SV-specific RT-PCR is used.