Orcein Content: 1.0% ± 0.1% w/v.
Acetic Acid Concentration: 45% ± 2% v/v.
Appearance: Deep purple, homogeneous solution.
Staining Performance: Clearly stains elastic fibers dark brown to black.
Filterability: Passes through filter paper without residue.
pH: 2.0-2.5.
Solubility: Complete dissolution, no undissolved particles.
Shelf Life: 12 months at room temperature.
Precipitation: No precipitation on standing.
Clarity: Clear when examined against light.
Specificity: Stains elastic fibers specifically when used properly.