Abstract
A new preparative method for cross-sectioning and staining of fibrous materials was developed and the differential staining was applied to reconfirm the bilateral structure of Merino wool fibers under an optical microscope observation. A part of a cross-section (ortho-cortex) of a Merino wool fiber was stained specifically by some selected basic dyes independent of pH of the medium while only at pH 6.86 by Acid Violet. The other part of the cross-section (para-cortex) was stained by Ponceau 2R at pH 6.86 at 60°C for 1h. The mechanism of differential staining of wool fibers having bilateral structure by basic dyes and acid dyes was investigated in detail.
