PD0325901, 25 mg

From STEMCELL Technologies, this small molecule is a selective, cell-permeable inhibitor of the MEK/ERK pathway that blocks MEK activation and downstream signaling. In C26 cells, it suppresses ERK phosphorylation with an IC₅₀ of 0.33 nM. The compound is supplied as a powder / crystalline solid with a stated purity of ≥98%.

Its chemical name is N-[(2R)-2,3-dihydroxypropoxy]-3,4-difluoro-2-[(2-fluoro-4-iodophenyl)amino]-benzamide, with molecular formula C₁₆H₁₄F₃IN₂O₄, molecular weight 482.2 g/mol, and CAS number 391210-10-9. Solubility in DMSO is reported at ≤ 20 mM. The product is stored at -20°C, protected from light, and is stated to be stable for 12 months from receipt. Stock solutions should be prepared fresh in DMSO; aliquoting is recommended to avoid repeated freeze-thaw cycles. For cell culture use, the compound should be diluted into medium immediately before use, with final DMSO concentration kept below 0.1% to avoid potential cell toxicity.

Published applications include maintaining undifferentiated mouse embryonic stem cells when combined with CHIR99021 in the absence of LIF, and supporting derivation and maintenance of rat ES cells. For reprogramming, the compound is used at later stages to select and expand fully reprogrammed mouse iPS cells, increases the efficiency of reprogramming human somatic cells to iPS cells in combination with SB431542 and Thiazovivin, promotes reprogramming of human somatic cells using only OCT4, and generates ground-state iPS cells from human and rat somatic cells when combined with CHIR99021 and A 83-01. The product is classified as hazardous — toxic if swallowed; may cause damage to organs through prolonged or repeated exposure; very toxic to aquatic life with long lasting effects — and users are referred to the Safety Data Sheet.