The present disclosure relates to antibody conjugates with binding specificity for folate receptor alpha (FOLR1) and its isoforms and homologs, and compositions comprising the antibody conjugates, including pharmaceutical compositions. The variable light chains are those of trastuzumab. Also provided are methods of producing the antibody conjugates and compositions as well as methods of using the antibody conjugates and compositions, such as in therapeutic and diagnostic methods. The antibody conjugates comprise a non-natural amino acid at a site selected from the group consisting of HC-F404, HC-K121, HC-Y180, HC-F241, HC-221, LC-T22, LC-S7, LC-N152, LC-K42, LC-E161, LC-D170, HC-S136, HC-S25, HC-A40, HC-S119, HC-S190, HC-K222, HC-R19, HC-Y52, or HC-S70, according to the Kabat, Chothia, or EU numbering scheme.