Western blot of reduced samples of concentrated CSF (lanes 1, 2) using MAb 1B11. Lane 1 contained concentrated CSF from a pool of low-NFL samples, whereas lane 2 contained concentrated CSF from a pool of high NFL. Lane 3, size markers. Lane 4, CSF pool (different pool compared to that used for lane 1 and 2) immunoprecipitated by MAb 1B11. Note that the bands detected in the IP sample appeared to be of the same MW as those in the concentrated CSF pool sample of lane 2. *, bands most likely representing heavy- and light-chain IgGs from antibodies used for immunoprecipitation. IP, immunoprecipitate. See also Supplementary Fig. 4 for an uncropped image of this Western blot. Molecular weights of SDS-PAGE size markers are indicated in kDa.