1. The original Arinkin technic of sternal puncture has been modified to include iliac, spinous process and tibial marrow aspiration.
2. There has been a need for improvement and standardization of the method of handling aspirated bone marrow.
3. An improved technic of marrow aspiration is described which combines direct Arinkin type smears with marrow particle and concentrate preparations. Fixed sections may also be obtained. An important innovation is the use of a dilute solution of sodium heparin in the aspirating syringe to prevent clotting so that all marrow obtained may be utilized.
4. The "pure" marrow fragment or particle smear is the most valuable for diagnostic purposes. Smears prepared from concentrated marrow cells and directly from the mixed aspirate are also studied routinely but are chiefly of value when marrow particle smears either can not be obtained or are unsatisfactory. Section of marrow particles is rarely indicated. Surgical trephine biopsy of the sternum is still performed when repeated aspirations fail to procure adequate marrow.
5. A gradual transition from the Arinkin method to the use of marrow fragments and concentrate smears is advisable because of the differences in cellular content and appearance of the preparations. A knowledge of the normal is essential.
6. The use of this combined technic of marrow aspiration has resulted in improved knowledge of normal and abnormal marrow obtained by the puncture method. It is of great value in the study of cells of the lymphocytic, plasmocytic and megakaryocytic series, and in routine search for the "L. E." cell. A higher degree of accuracy has been attained in diagnosis than was possible by the Arinkin technic. The procedure is especially valuable in the diagnosis of lymphosarcoma, plasma cell myeloma, thrombocytopenic purpura, leukopenic and pancytopenic states, hypoplastic and aplastic anemias and aleukemic leukemias.