Method for detection of aggregates in biological samples

1. A method for detecting one or more tau aggregates in a biological sample, the method comprising the steps of: (a) providing at least one mammalian cell comprising a first protein linked to a first reporter and a second protein linked to a second reporter, wherein the first protein and the second protein each comprise a similar aggregation-prone domain, such that the first protein and the second protein aggregate and produce a detectable signal; (b) contacting the at least one mammalian cell with a biological sample comprising a protein aggregate at a concentration equivalent to about 1 pM to about 100 nM of monomers, the protein aggregate comprising an aggregation-prone domain similar to the first and second protein, such that the protein aggregate is taken up by the cell; (c) measuring a fluorescence resonance energy transfer (FRET) signal by flow cytometry; and (d) comparing the amount of the detectable signal in the biological sample to the amount of a detectable signal produced by a control, wherein a change in the detectable signal indicates one or more protein aggregates are in the biological sample, wherein the mammalian cell is a HEK293T cell, the aggregation-prone domain of the first and second protein comprises a tau repeat domain with a P301S mutation, the first reporter is CFP and the second reporter is YFP.

2. The method of claim 1 , wherein the biological sample is brain lysate.

3. The method of claim 1 , further comprising an additional step before contacting the at least one mammalian cell with the biological sample, the additional step selected from the group consisting of (i) sonicating the biological sample, and (ii) a lipid-based transfection reagent.

4. The method of claim 2 , wherein the biological sample is in contact with the at least one mammalian cell for at least 4 hours.

5. The method of claim 1 , wherein the mammalian cell is a tau RD P301S monoclonal line ATCC CRL-3275.