Abstract: The present invention generally relates to microfluidic droplets and, including forming gels within microfluidic droplets. In some aspects, a fluid containing agarose or other gel precursors is transported into a microfluidic droplet, and caused to harden within the droplet, e.g., to form a gel particle contained within the microfluidic droplet. Surprisingly, a discrete gel particle may be formed even if the fluid containing the agarose or other gel precursor, and the fluid contained within the microfluidic droplet, are substantially immiscible. Other aspects of the present invention are generally directed to techniques for making or using such gels within microfluidic droplets, kits containing such gels within microfluidic droplets, or the like.