Silver express kit

Example 11

Purified preparations of tau352 and tau441 were incubated at a 1:1 ratio or 1:4 ratio of tau352:tau441 at 37° C. in pH neutral buffer for 45 min. or 2 days. Non-reducing sample buffer was used to prepare samples for SDS-PAGE using a 4-20% gradient gel (BioRad) to resolve purified tau monomer, dimer, trimer and tetramer. Silver staining was performed with the Silver Express kit (Invitrogen) (shown in FIG. 19).

The references below are hereby incorporated in the present disclosure for all that they disclose.

Example 5

Recombinant human Tau441 protein was expressed in bacteria using standard methods and purified using cation exchange with SP Sepharose and size fractionation using continuous gel electrophoresis (BioRad). The protein was incubated at 1 mg/ml in 50 mM Tris-Hcl pH 7.4. SDS-PAGE using a 4-20% gradient gel (BioRad) was used to resolve the oligomeric species. Silver staining was performed with the Silver Express kit (Invitrogen) (shown in FIG. 10).

Example 8

Tau441 dimer and timer aliquots were incubated in 1× Tris/glycine/SDS running buffer with no NaCl, 100 mM or 200 mM NaCl for either 15 or 60 minutes. SDS-PAGE using a 4-20% gradient gel (BioRad) was used to resolve the protein in the samples. Non-reducing sample buffer was used to prepare samples for SDS-PAGE using a 4-20% gradient gel (BioRad) to resolve purified tau monomer, dimer, trimer and tetramer. Silver staining was performed with the Silver Express kit (Invitrogen) (shown in FIG. 13).

Example 10

Purified preparations of tau352 or tau441 were incubated at 37° C. in neutral buffer with a very low concentration of hydrogen peroxide to create an oxidizing environment that would not lead to protein degradation. Non-reducing sample buffer was used to prepare samples for SDS-PAGE using a 4-20% gradient gel (BioRad) to resolve purified tau monomer, dimer, trimer and tetramer. Silver staining was performed with the Silver Express kit (Invitrogen) (shown in FIG. 15).