Figure 5.

Detection of ERK1, ERK2, and doubly phosphorylated ERK2 in a pooled human CSF sample. Following prefractionation of 3.25 mL of pooled CSF on an Off-gel fractionator, the proteins with isoelectric points in the pH range from ~6.5 to ~8.5 were pooled, precipitated with trichloroacetic acid, and analyzed by SDS-PAGE/Western blot with the indicated antibodies. A sample corresponding to ~0.54 mL of the original CSF-pool was loaded on each lane. (1) Magic mark protein standard, (2) CSF pool, (3) positive control (cell lysate of okadaic-acid-treated SH-SY5Y cells).