Our laboratory studies proteins comprising the nuclear pore complex, the exclusive site of nucleocytoplasmic transport. The expression of recombinant NPC components remains a technical challenge since many of these,30 nucleoporins possess low solubility and molecular weights in excess of 100 kD. Previously, we found that the nonameric subcomplex Nup107160 is essential for pore assembly. Attempts to study interactions of its components have met with limited success principally because larger components of the Nup107-160 complex were insoluble when expressed in heterologous systems. However, all of the associated nucleoporins including Nup160, one of the largest members of the Nup107-160 subcomplex, could be efficiently translated using reticulocyte lysates. Each of the TAP-tagged nucleoporins was then incubated with equal volumes of his-Nup160 lysate and immobilized on,5 Ni-NTA beads. After the addition of streptavidin-coated QDs, beads were isolated and imaged on the surface by confocal microscopy. In a similar manner we imaged direct interactions between Nup96 and Sec13, as well as between Nup107 and Nup133. These findings, which are consistent with the yeast data previously reported, confirm that SINBAD is a useful tool to study protein-protein interactions. Next we tested if SINBAD can be used to decrease the amount of cell lysate required to perform a pull-down an Cefetamet pivoxil HCl endogenous proteins from cell homogenates. We incubated Ni-NTA beads coated with his-RanQ69L with different volumes of hypotonic 293T cell extracts to pull down endogenous Importin b that was visualized using anti-Importin b and QD-labeled secondary antibodies. We found that the equivalent of 50 cells was sufficient to detect the association of RanQ69L to Importin b. Importantly, by Western blotting at least 7000 cells were required. By comparative Western blotting, we calculated that the amount of Importin b from 50 cells was 35 pg. These data are Gelsenicine further evidence that SINBAD is a useful method to study protein-protein interactions when cell material is limiting such as with stem cells or rare tissue samples.