Abstract: The disclosure provides methods of forming one or more single-cell proteomic samples, such as by: dispensing n droplets of lysis buffer onto a substantially planar solid surface, wherein n>2: dispensing a single cell into each of the n droplets of lysis buffer to produce n droplets with a lysed single cell: dispensing digestion buffer into each of the n droplets to digest proteins from each lysed single cell to produce n droplets comprising peptides: dispensing a chemical tag into at least a subset of the n droplets comprising the peptides to produce labeled peptides, thereby enabling the labeled peptides in a given droplet to be distinguishable from labeled peptides in at least one other droplet: and applying a fluid to merge at least a subset of the droplets into a combined droplet on the substantially planar surface, thereby combining the labeled peptides to form a single-cell proteomic sample.

Abstract: A filter assembly and methods of using the filter assembly are disclosed. The filter assembly includes a proximal portion including support members and a distal portion including a mesh. The filter assembly may also include additional portions including additional meshes or support members. The proximal portion of the filter has a first major diameter, and the distal portion of the filter has a second major diameter. In a first unconstrained state, the second major diameter of the filter is less than the first major diameter of the filter. According to certain aspects of the disclosure, the filter assembly further includes a filter wire and a tubular member that may be attached to a proximal or distal end of the filter.