
Product numbers 10210, MAL-dPEG®4-t-boc hydrazide, 10961, MAL-dPEG®8-t-boc hydrazide, and 10962, MAL-dPEG®12-t-boc hydrazide, are cross-linking compounds that react with a free thiol on the maleimide side of the molecule and then (following deprotection of the t-boc group) with an aldehyde or amine to form a hydrazone bond.