Interphase Fluorescence in situ Hybridization of Bone Marrow Smears of Multiple Myeloma

Fluorescence in situ hybridization (FISH) detection is an indispensable method in genetic risk stratification in multiple myeloma (MM), which is one of the most common hematological malignancies. The identifying characteristic of MM is accumulated malignant plasma cells in bone marrow. FISH reports for MM mainly focus on purified or identified clonal plasma cells, rather than all nucleated cells, by sorting with anti-CD138 magnetic beads or marking with cytoplasmic immunoglobulin light chain κ or λ. Bone marrow interphase nuclei are usually obtained from fresh bone marrow cells. However, satisfactory enrichment of plasma cell specimens requires large amounts of fresh heparin anti-coagulated bone marrow, which cannot be obtained in the case of difficult bone marrow extraction or a bone marrow dry tap. Herein, we establish a novel method to improve the success of FISH detection on stained or unstained bone marrow smears. Bone marrow smears are easier to obtain than anticoagulated bone marrow specimens.