A device comprising a holder and a carrier for the holder, a. the holder having a top portion and a bottom portion, each top and bottom portion having an outer edge, a top surface and a bottom surface and a thickness between the top and bottom surfaces, the top portion having an opening inward of the outer edge, wherein a flow distributor covers the opening when said holder is closed, the holder comprising: (i) a frame having a perimeter edge configured to support a protein blotting membrane, said frame being constructed of plastic or paper; (ii) a flow distributor being a membrane attached to said frame and over which said protein blotting membrane can be positioned; (iii) a porous support which is a polypropylene non-woven mesh bound to said frame along one edge, and a sheet of paper laminated to said polypropylene mesh, wherein the porous support allows access to the holder for a user of the device to add the protein blotting membrane to the holder when the holder is open, such that said protein blotting membrane would be sandwiched between the flow distributor and the porous support when said holder is closed; and b. the carrier for the holder being comprised of a top plate and a bottom plate, each having a width and a length, a top and bottom surface and a thickness between the top and bottom surfaces, an outer edge and at least one opening, the plates being of a length and width greater than the length and width of the holder, the top plate of the carrier having an opening substantially equal in width and length to the opening of the top portion of the holder, the bottom surface of the top plate and the top surface of the bottom plate each having one or more seals in alignment with each other when the two plates are adjacent each other and the seals being arranged on each surface at a width and length greater than that of the opening of the top plate, but less than the outer dimensions of the holder, at least one of the plates has an additional seal formed adjacent the outer edge of the plate and outward of the seal of that plate. a. the holder having a top portion and a bottom portion, each top and bottom portion having an outer edge, a top surface and a bottom surface and a thickness between the top and bottom surfaces, the top portion having an opening inward of the outer edge, wherein a flow distributor covers the opening when said holder is closed, the holder comprising: (i) a frame having a perimeter edge configured to support a protein blotting membrane, said frame being constructed of plastic or paper; (ii) a flow distributor being a membrane attached to said frame and over which said protein blotting membrane can be positioned; (iii) a porous support which is a polypropylene non-woven mesh bound to said frame along one edge, and a sheet of paper laminated to said polypropylene mesh, wherein the porous support allows access to the holder for a user of the device to add the protein blotting membrane to the holder when the holder is open, such that said protein blotting membrane would be sandwiched between the flow distributor and the porous support when said holder is closed; and b. the carrier for the holder being comprised of a top plate and a bottom plate, each having a width and a length, a top and bottom surface and a thickness between the top and bottom surfaces, an outer edge and at least one opening, the plates being of a length and width greater than the length and width of the holder, the top plate of the carrier having an opening substantially equal in width and length to the opening of the top portion of the holder, the bottom surface of the top plate and the top surface of the bottom plate each having one or more seals in alignment with each other when the two plates are adjacent each other and the seals being arranged on each surface at a width and length greater than that of the opening of the top plate, but less than the outer dimensions of the holder, at least one of the plates has an additional seal formed adjacent the outer edge of the plate and outward of the seal of that plate.