Methods and kits are provided for amplifying and detecting Aβ proteins from samples, for example, from patients having Alzheimer's Disease. For example, a method for determining a presence of a soluble, misfolded Aβ protein may include contacting the sample with a monomeric, folded Aβ protein to form an incubation mixture; conducting an incubation cycle two or more times on the incubation mixture effective to form an amplified portion of misfolded Aβ protein; incubating the incubation mixture effective to cause misfolding and/or aggregation of at least a portion of the monomeric, folded Aβ protein; physically disrupting the incubation mixture effective to at least partly de-aggregate at least a portion of a misfolded Aβ aggregate present; and determining the presence of the soluble, misfolded Aβ protein in the sample by detecting at least a portion of the amplified portion of misfolded Aβ protein.