Prepare films and fix and stain, as for blood films. For sections, fix the marrow in formol-Müller’s, mercuric chloride, Zenker’s, etc.; imbed in paraffin; cut very thin sections; stain with Ehrlich’s triple stain or Wright’s modification of Leishman’s stain. To distinguish the young forms of erythrocytes and leukocytes Trambusi fixes in Flemming’s, stains the sections in a 1 per cent thionin solution in aniline-water (4:100), differentiates in acid-alcohol, and then brings the sections into a watery eosin and finally an alcoholic eosin, and mounts in xylol-balsam.
Spleen and Lymphnodes.
Fresh material may be obtained by means of a trocar, and may be examined in the fresh state, or films may be prepared, fixed and stained, as for blood-smears. Sections of fixed tissues may be obtained by the use of the same fixing and staining methods employed in the study of the blood or bone-marrow. For the study of the reticulum Mallory’s reticulum stain or the digestion-method may be used. In ordinary work formol-fixation followed by eosin-staining is of great value in distinguishing hæmolymphnodes and lymphatic glands.
II. BONE.
For ordinary work decalcification is necessary except for those pathologic conditions in which the lime-salts have been lost (see Chapter [XXI]). Imbed in celloidin preferably. When decalcification has been carried out place sections in an alkaline solution before staining, and stain for a longer period than usual. Methylene-blue and eosin stain osteoblasts and osteoclasts very well. Van Gieson’s is an especially useful stain for ordinary work; osteoid tissue is red, calcified areas yellow. Sections of bone without decalcification can be prepared by fixing, hardening and staining in bulk; the bone is then sawn in the dried condition, and the sections ground down to the required thickness. Schmorl’s methods for the preparation of bone-sections have practically superseded all other staining methods.
Schmorl’s Thionin-picric-acid Method.
1. Fix in formol or formol-Müller’s preferably.
2. Decalcify in formol-nitric acid or Ebner’s alcoholic HCl acid solution.
3. Wash thoroughly in water. After-harden in increasing strengths of alcohol; freeze or imbed in celloidin (not paraffin); cut.
4. Transfer sections to water for 10 minutes.