Probing spin-charge separation using spin transport

Pedagogical discussions are given on what constitutes a signature of spin-c harge separation. A proposal is outlined to probe spin-charge separation in the normal state of the high T-c cuprates using spin transport. Specifical ly, the proposal is to compare the temperature dependences of the spin resi stivity and electrical resistivity: Spin-charge separation will be manifest ed in the different temperature dependences of these two resistivities. We also estimate the spin diffusion length and spin relaxation time scales, an d we argue that it should be experimentally feasible to measure the spin tr ansport properties in the cuprates using the spin-injection technique. The on-going spin-injection experiments in the cuprates and related theoretical issues are also discussed.