The present invention relates to the field of electrophoresis and more specifically to a gel or strip for separating peptide components by isoelectric focusing by producing IPG (immobilized pH gradient) gels or strips in a novel way before focusing. More closely, the peptides are focused in a novel IPG gel including an uneven or non-linear pH gradient having at least three separate stepwise arranged pH-intervals. After focusing the peptide resolution is high and the peptides are evenly distributed along the gel.