A new method to measure cellular toxicity of non-fibrillar and fibrillar Alzheimer's Abeta using yeast.

The 42 amino acid amyloid-beta (Abeta) can exist in multiple physical states including oligomers and fibrils. This study shows that fibril formation is hastened by the biological buffers required to support the growth of mammalian cells, but is prevented if Abeta is maintained in water. Here we describe a method to produce Abeta in oligomeric form and the comparison of stable fibrillar and non-fibrillar forms in cell toxicity studies in water, achieved through the use of yeast. We show that extracellular, non-fibrillar Abeta causes a dose dependent loss of cell viability while fibrillar Abeta has low toxicity.