Dox-btn2 is a biotin labeled Doxorubicin (HY-15142A), with a biotin label at the point of conjugation to doxorubicin at 3-NH2. Dox-btn2 can be used for cell imaging. While Doxorubicin is mainly accumulated in the nucleus, while Dox-btn2 is mainly located in the cytoplasm[1].