PYCARD therefore represented a stringent validation test of the methylation arrays.
Due to the unexpected high rate of suspected off-target hits, we wanted to obtain more stringent validation of our hits and therefore performed a tertiary screen using four additional independent siRNAs that were chemically modified to reduce the chance of off-target effects.
Unlike human iPSCs, the four murine secondary iPSCs in our study shared the same genetic background and passed the most stringent validation of pluripotency through tetraploid complementation.
In our study, the four secondary iPSC lines derived from three germ layers all passed the most stringent validation of pluripotency through tetraploid complementation and produced viable all-iPSC mice.
After the most stringent validation of pluripotency, the four iPSC lines derived from the three germ layers of the viable all-iPSC mice were selected for the following experiments.
We then performed a more stringent validation using in situ hybridization.
A culture of stringent validation has been developed for such approaches (Leist et al. in ALTEX 27(4):309–317, 2010; ALTEX 29(4):373–88, 2012a; Toxicol Res 1 8 22, 2012b), while the quality and usefulness of animal experiments have been little scrutinized.
Recently, a more stringent distance of 500 bp was used, and we will also use this more stringent validation for reference to earlier work (Abeel et al., 2008; Goni et al., 2007).
Protein identification was accomplished by a bioinformatics platform combining two database search engines, Mascot [ 25] and Phenyx [ 26], and an innovative and very stringent validation strategy enforcing a maximum false discovery rate (FDR) of 0.25% on protein groups [ 27].
In this article, we discuss how errors in these models arise and how they can be evaluated, and we argue for even more stringent validation checks and documentation of structures before deposition with the Protein Data Bank.
In the developed workflow, a stringent protocol [22] of model validation is followed to ensure robustness and predictive power of the constructed models.
