D-Pen amino acid product blog Tags: Amino Acid; D-Pen; D-Pen amino acid; Posted by mybiosource_staff on . The D-Pen n/a (Catalog #MBS405334) is an Amino Acid and is intended for research purposes only. The product is available for immediate purchase.To buy or view more detailed product information and pricing, please click on the technical datasheet page below:D-Pen(M.W. 149.21) C5H11NO2S [52-67-5].Cas Number: 52-67-5.