Abstract: A method and apparatus is described herein which allows filters, to which bacterial or mammalian cell samples have been absorbed, to be reacted sequentially by various scientific means and to be washed between analyses. The filters are placed between interconnected parallel separation plates on the filter agitator. The filter holder is lowered into a reaction container that contains reaction or wash solutions. The filter holder is raised or lowered in the reaction container by physical or mechanical means. The reaction container is covered by a lid which prevents splashing and contamination of the solution or filters. Solutions are added by means of a fill tube located in the lid and emptied by means of a drain in the reaction container. Once the sequential analysis is complete, gene product on the sample filters is detected by an appropriate method.