coli. The activity as well as the specificity of the two enzymes were tested by hydrolyzing a 0.5 % solution of KC1 and IC1 at 37 °C for 24 h. To gain insights into the extent of carrageenan hydrolysis, the hydrolysates were analyzed by HPSEC-RI (Fig. ). This approach allows for the reliable detection of general hydrolytic activity as well as the detection of high molecular weight blocks which are resistant to hydrolysis by the individual enzymes. To analyze the oligosaccharides liberated by κ-or ι-carrageenase, the hydrolysates were also analyzed by HPLC-MS (Fig. ). A HILIC column was selected for chromatographic separation of the carrageenan oligosaccharides and MS detection was carried out after electrospray ionization in negative mode. By using this setup, dimeric repeating units as well as oligosaccharides with a higher molecular weight could be detected.