Gel electrophoretic distinction between Congo Red nonreactive beta‐amyloid (1—42) and beta‐amyloid (1—40)

Congo‐Red nonreactive beta‐amyloid (1—42) exibits in gel electrophoresis (pH 8.82, 0.01 M ionic strength, 2°C) a surface charge density larger than that of the corresponding peptide of length (1—40), and a size indistinguishable from that of (1—40).