The invention includes a forceps and collection assembly for acquiring and storing a plurality of tissue samples in a single pass, and accompanying mechanisms for use with the forceps and collection assembly. The accompanying mechanisms include an endoscope working channel cap assembly configured to minimize compression of a pouch of the forceps and collection assembly as it traverses a seal of the cap assembly, and a flush adapter configured to be coupled to the pouch so as to assist in removing tissue samples in the pouch by flowing fluid through the pouch.