Binding of MG sera to the titin fragments by ELISA. Sera (from 10 MG patients and a healthy control, HC) were incubated with immobilized fragments: whole MIR, its domains I109-I110, I110-I111, I110 and I111, and the titin fragments outside the MIR region: M1-M2, I99-I101, titin kinase region A170-Kin-M1, and A160-A170. (A) It is shown that all sera were bound to all 3 fragments which contain the I110 domain, practically equally well with their binding to the whole MIR, but not to any other fragment. (B) Average percentages of antibody binding of the 10 sera to I109-I110, I110-I111, and I110, versus the values of antibody binding to the MIR. The differences are not statistically significant.