Lysine-specific histone demethylase 1A（LSD1）, also known as KDM1A (lysine-specific demethylase 1A) or AOF2 (flavin-containing amine oxidase domain-containing protein 2), is a type of histone modification enzyme.It is known to specifically remove methyl groups from lysine residues on histone proteins, thereby regulating chromatin structure and gene expression. LSD1 plays a critical role in various biological processes, including cell cycle progression, apoptosis, and tumorigenesis.RCOR1,?LSD1, and?HDAC1?can form stable, enzymatically active, stoichiometric ternary complexe.Thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human LSD1 and recombinant human HDAC1. Briefly, biotin-linked LSD1 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to HDAC1-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50μl stop solution to the wells and read at 450nm immediately. The binding activity of recombinant human LSD1 and recombinant human HDAC1 was shown in Figure 1, the EC50?for this effect is 4.35ug/mL.