The present invention provides compositions for the production of an antibody or functional fragment thereof directed against Thomsen-nouvelle (Tn) antigen (CD175) or a sialylated from thereof (sTn antigen, CD175s). The compositions disclosed herein include isolated antibody or functional fragments thereof that binds to Tn antigen or sTn antigen and polynucleotides encoding the heavy chain and/or a light chain variable domains of such antibody or functional fragment. The invention also provides methods of treating or preventing a disease, such as cancer or tumor formation, wherein the antibody or functional fragment includes a variable heavy chain domain and a variable light chain domain that has an amino acid sequence provided herein. The invention further provides a conjugate of an antibody or functional fragment thereof conjugated or recombinantly fused to a localizing agent, detectable agent or therapeutic agent, and methods of treating, preventing or diagnosing a disease in a subject in need thereof.
