Methods and systems for purifying cells and/or viruses are provided. The sample is added to a well disposed in a medium. A potential is applied across the medium to cause the contaminants to enter one or more walls of the well, and retain the cells and/or viruses in the well. The cells and/or viruses can be removed from the well, and optionally adhered or fixed to a surface, or detected. In one embodiment, the cells and/or viruses may be retained in the well by embedding in the medium. The medium including the embedded cells and/or viruses may be excised or otherwise removed and transferred to a glass slide or other solid surface.