The key techniques of in situ hybridization (ISH) currently in use include _______________________________________. DNA ISH can be used to determine the structure of chromosomes. Fluorescent DNA ISH (FISH) can be used in medical diagnostics to assess chromosomal integrity. RNA ISH is used to measure and localize RNAs (mRNAs, lncRNAs, and miRNAs) within tissue sections, cells, whole mounts, and circulating tumor cells (CTCs).