dimers of desmin ( from chicken gizzard ) , vimentin ( from bovine lens tissue and cultured human fibroblasts ) and the neurofilament protein nf-l ( from bovine brain ) as well as in vitro formed homodimers of human and rat cytokeratins numbers 8 ( a ) , 18 ( d ) and 19 ( `` '' 40k '' '' ) , are characterized by ultracentrifugation techniques ( sedimentation velocity and equilibrium ) , electron microscopy and chemical cross-linking .
C0042666
vimentin
C0086418
human