Patent ID: 8206665

Claim:
A plurality of caps for microtubes for use with a tube-storage rack having wells arranged in a matrix, and an alignment plate adapted to overlie the storage rack, and having cells with open tops and bottoms arranged in an identical matrix, the alignment plate having intersecting partitions forming a grid dividing the plate into the matrix of cells, the matrix of cells having a pitch equal to the pitch of tube-receiving wells of the tube-storage rack, the wells adapted to receive a plurality of microtubes having open upper ends, the alignment plate adapted to receive a plurality of said caps and being operable to align the caps with the cells of the alignment plate for displacement into the open ends of microtubes positioned in the wells of the storage rack, and after the alignment plate is placed over the storage rack, allow the aligned caps to be simultaneously pushed through the cells into the open ends of the microtubes to close the open ends, characterized in that each of said plurality of caps for microtubes has a plug portion at a front end, which is dimensioned to be inserted into the open end of the microtube, and a grip portion at the rear end having an outer circumferential diameter larger than an outer circumferential diameter of said plug portion, and dimensioned to protrude from the open end of the microtube, the entire length of each said cap including said plug portion and said grip portion is longer than the pitch of the alignment plate cells, and shorter than twice said pitch, each said cap being composed of a resilient compressible material of sufficient resilience to be compressed when said cap is pushed through the alignment plate cell into the open end of the microtube in the race, said grip portion has a rear edge surrounded by an easily deformable collar having an outer circumferential diameter larger than the diameter of the alignment plate cells, said collar preventing entry of the grip portion into the cells of the alignment plate until said collar is deformed when said caps are pushed through the cells into the open upper ends of the microtubes in the wells, said plug portion of said cap has a tapered front end part which is tapered toward said front end, and said cap has a center of gravity within said plug portion to cause said front portion of said cap to fall into the open top of one of the cells of the alignment plate for pushing into the open end of the microtube in the underlying well.