Abstract: A method for preparing a .sup.195m Au-containing liquid is provided. In the method, .sup.195m Hg is adsorbed on an adsorption agent and then the daughter radioisotope .sup.195m Au is eluted from the adsorption agent with an eluant containing a gold-complexing agent. The adsorption agent comprises a mercury ion-binding material having a substantially stronger adsorption affinity for mercury ions than for gold ions.Also disclosed are a radioisotope generator capable of producing a .sup.195m Au-containing liquid and a process for conducting a radiodiagnostic examination on a warm-blooded animal using a .sup.195m Au-containing liquid.