The MIND/Ndc80c linkage can withstand substantial load. (A) Representative traces of bead position versus time for 20 nM MIND-His/Ndc80c-FLAG beads tracking with assembling and disassembling microtubule tips under 1.7–2.5 pN of force applied in the direction of microtubule assembly. Traces are arbitrarily offset on the y axis for visual clarity. (B, Left) Survival probability vs. force for 20 nM Ndc80c-His (N-H, n = 20), 20 nM MIND-His/Ndc80c-FLAG (M-H/N-F, n = 32), and 20 nM MIND-His beads with 40 nM Ndc80c-FLAG and 2 nM Dam1c-FLAG (M-H + N-F + D-F, n = 50). (Right) Average rupture force derived from the distributions on the Left. Ndc80c-His and MIND-His/Ndc80c-FLAG were not significantly different, P = 0.26, two-tailed Student’s t test. Error bars denote SEM.