Dianol

DIANOL, chlorodioxyacetic acid, a transparent yellowish liquid with a characteristic odor. In microscopic technique it is used for: 1) softening hard tissues, mainly chitin and keratin, to facilitate their cutting on a microtome, 2) decolorizing (depigmenting) stained tissue elements of animal and plant origin, and 3) microchemical determination of cellulose, hemicellulose, resp. pectosans, and chitin. Method of application when embedding: fixed and hardened pieces are rinsed with 63° alcohol and transferred to dianol until complete softening, resp. decolorization (sometimes it is necessary to change the D.), after which they are passed through alcohols (63°→100°) and chloroform or tetralin into paraffin. Thus, even whole small insects (lice, fleas, mosquitoes, etc.) can be embedded, after first separating the limbs and making an incision in the abdomen. All operations with D. must be performed in the dark. D. does not alter the histological structure of tissues and does not affect subsequent staining. Initially, D. was a solution of SO₂ and C₂O₄ in 50% CH₃COOH (R. Schulze). However, due to swelling of histological objects in acetic acid, the latter was replaced by H₂SO₄ or HNO₃. D. is sold ready-made by the Leitz firm (Leitz, Berlin) at a price of 6.5 marks for 500.0 cm³.