To determine which species of tau are associated with membranes, the membrane fractions prepared from 28 DIV wild-type and 3xTg-AD slice cultures were immunoblotted with primary antibodies directed against the N terminus (TP007) and C terminus (TP70) of tau.46, 47 Membranes of both wild-type and 3xTg-AD slice cultures contain predominantly full-length tau species of 50–64 kDa with intact N- and C- termini (Figure 5c). This evidence concerns the gene MAPT and Alzheimer disease.