pLentG-KOSM is a simple lentiviral vector in which defined factors are in-frame fused into a single open reading frame (ORF) via self-cleaving 2A peptides and are controlled by a CMV promoter. The transcription factor ORF is followed by IRES-GFP as a reporter for viral transduction.
Producing iPS cells using pLentG-KOSM not only provides higher efficiency than other methods, but also reduces time and reagent cost by allowing you to package a single lentivirus rather than several viruses each containing a single gene.
Figure 1: Expression of Stem Cell Factors. pLentG-KOSM vector was transiently transfected into 293T cells. Top: Correct processing of each factor was confirmed by Western blot analysis. Expression vectors individually containing Klf4, Oct3/4, Sox2 and c-Myc were included as positive controls. Bottom: Representation of flow cytometry analysis of GFP-expressing MEFs 3 days after infection.
Figure 2: Characterization of iPS cell colonies generated from MEFs infected with lentivirus containing KOSM fusion gene. Top: Staining of pluripotency markers in induced cell colonies (200x magnification). Bottom: AP staining (100x magnification) and morphology (40x magnification) in induced ES cell-like colonies.