since immunoglobulin m ( igm ) antibody activity detected by rphi was destroyed by pretreatment of serum with dithiothreitol ( ddt ) , whereas dtt-resistant antibodies such as igg remained unchanged , the titer of igm antibody could be distinguished from that of dtt-resistant antibody by comparing the results of two rphi tests performed with and without dtt pretreatment .
C0020852
antibodies
C0003241
antibody