PEGylated Standards are for use in mass spectrometry, molecular biology, and life science laboratories. Protea's standards are high quality for use in the calibration of protein analyses by LC-MS analytical systems and other applications. For quality assurance and standardization purposes, each standard protein is provided with a mass spectrum of the protein. Our protein standards also provide an excellent sample for method development of PEGylated protein separation, as well as enzymatic digestion studies and characterization of LC-MS analytical systems. PEGylated Myoglobin (PS-011) is provided as a mixture of unmodified and monoPEGylated myoglobin species.