Any useful tips for transitioning/thawing cell culture in DEF-CS?

Make sure to seed the cells dense, especially the first couple of passages (it did look a little bit sparse in the images as compared to our images even though 100k/cm2 was seeded. It might be that the cells do not attach so well, could be worth an even higher start density). Do allow the cells to grow quite dense the first passage, so that the cells are not passaged to early, it [...]

Is this possible and what is the advantage to growing iPS cells in suspension?

Yes. Suspension cultures allow similar expansion of hPSCs as compared to conventional 2D culture, and possibly requiring less media volumes per cell. Further, differentiation towards certain specialized cells will sometimes give a better/different maturation depending on what is the aim (examples of specialized cells are beta cells and hepatocytes). Toxicology studies have in the past [...]

How is IFU/ml calculagted from the GoStix Value (GV, ng/ml p24)

1. To calculate the actual IFU/ml for an unknown stock, a reference virus (a virus stock for which the IFU/ml is known) must first be tested to obtain both an infectious unit value as well as a GV. 2. Calculate the IFU/GV ratio for the reference virus. 3. Analyze the unknown sample using Lenti-X GoStix Plus to obtain the GV (ng/ml p24). 4. Perform calculations to determine your IFU/ml (see [...]

What is the experiment to associate GV with functional titer?

As with all other titration methods (e.g., p24 ELISA, or qRT-PCR) used to produce comparable titer quantitation between experiments, the following variables must be consistent: lentiviral packaging systems, lentiviral vectors, transfection methods, harvest times, and scanning devices. We recommend first testing a sample of known titer to determine the corresponding GV titer provided by the kit. [...]

What is the experiment to associate GV with functional titer?

As with all other titration methods (e.g., p24 ELISA, or qRT-PCR) used to produce comparable titer quantitation between experiments, the following variables must be consistent: lentiviral packaging systems, lentiviral vectors, transfection methods, harvest times, and scanning devices. We recommend first testing a sample of known titer to determine the corresponding GV titer provided by the kit. [...]