Cross-linking is an enzyme immobilization technique in which enzymes are cross-linked with each other without any support material, so the enzymes act as their carrier. 

Disadvantages of Cross Linking 

• Requires enzymes to be in crystallized form, which requires highly pure enzymes, making this a very expensive technique
• Inhibits enzyme activity 
• Enzymes are susceptible to denaturation by the polyfunctional chemicals used in this method