We have immobilized human Lys plasmin on agarose resin by coupling of primary amines. Plasmin retains catalytic activity when coupled and may be used to efficiently activate single-chain tPA and uPA to the two-chain form (1). It may also be used to convert plasminogen from its native Glu form to the Lys form by removing the first 77 amino acids. References: 1. Wallen, P. et al. (1982) Biochim. Biophys. Acta 719:318-328.