Capillary electrophoresis in acidic, isoelectric buffers is a novel methodo
logy allowing fast protein and peptide analysis in uncoated capillaries. Du
e to the low pH adopted and to the use of dynamic coating with cellulose de
rivatives, silanol ionization is essentially suppressed and little interact
ion of macromolecules with the untreated wall occurs. In addition, due to t
he low conductivity of quasi-stationary, isoelectric buffers, high-voltage
gradients can be applied (up to 800 V/cm) permitting fast peptide analysis
with a high resolving power due to minimal diffusional peak spreading. Four
such buffers are here described: cysteic acid (Cys-A, p/1.85), iminodiacet
ic acid (IDA, p/2.23), aspartic acid (Asp, p/2.77) and glutamic acid (Glu,
p/3.22). A number of applications are reported, ranging from food analysis
to the study of folding/unfolding transitions of proteins.