S-acetyl-PEG12-alcohol is a PEG linker containing a sulfur acetyl group and an alcohol group. The sulfur acetyl can be deprotected to generate thiol groups. The alcohol group can be reacted to further derivatize the compound. The hydrophilic PEG linker increases the water solubility of the compound in aqueous media. Longer PEG chains enhance the water solubility properties of compound compared to shorter PEG chains.