Embodiments of the present invention relate to techniques for improving optofluidic microscope (OFM) devices. One technique that may be used employs surface tension at a hydrophobic surface to passively pump the fluid sample through the fluid channel. Another technique uses electrodes to adjust the position of objects in the fluid channel. Another technique computationally adjusts the focal plane of an image wavefront measured using differential interference contrast (DIC) based on Young's interference by back propagating the image wavefront from the detection focal plane to a different focal plane. These techniques can be employed separately or in combination to improve the capabilities of OFM devices.