text: DCC (acronym for N,N-dicyclohexylcarbodiimide) was one of the first carbodiimides developed as a reagent. It is widely used for amide and ester formation, especially for solid-phase synthesis of peptides. DCC has achieved popularity mainly because of its high-yielding amide coupling reactions and the fact that it is quite inexpensive.
  However, DCC does have some serious drawbacks, and its use is often avoided for several reasons:
  #The byproduct N,N-dicyclohexylurea is mostly removed by filtration, but trace impurities can be difficult to remove. It is incompatible with traditional solid-phase peptide synthesis. 
  #DCC is a potent allergen, and repeated contact with skin increases the probability of sensitization to the compound. Clinical reports of individuals who cannot enter rooms where peptide coupling agents are used have been reported.