Patent GB-1115297-A (GB)
Title: Sediment container and cap
IPC: B01L3/14
Filed: 1966-10-31
Abstract: 1,115,297. Specimen containers for centrifuges. CLAY-ADAMS Inc. 31 Oct., 1966 [7 Feb., 1966], No. 48757/66. Heading B2P. [Also in Divisions B8 and C2] A tubular container for use in a centrifuge for separating a specimen of sediment-containing liquid, such as wine, into its constituents has open and closed ends, the closed end having a part, of smaller cross-section than that of the remainder of the container, forming a reservoir 25 for receiving the sediment during separation, the container being provided with a cap 21 which is arranged to fit over and seal its open end. The container and cap may be made of moulded plastics. The length and cross-section of the reservoir are such that when the container contains a liquid such as wine and is inverted after centrifugation for decanting the supernatant liquid, the sediment and a small amount of the supernatant liquid is retained in the reservoir by the combined action of surface tension and atmospheric pressure. A skirt portion 22 surrounding the reservoir 25 has a flat base 27 which allows the container to stand by itself on a flat surface. A rib 28 or a groove on the outer surface of the container serves as an indication of the required amount of liquid to be placed in the container. The wall of the container at its open end tapers to a sharp edge 26 to facilitate pouring of liquid. The cap 21 has a central portion 31 spaced from a surrounding skirt portion 30 having an annular shoulder 32 which sealingly engages the extremity of the edge 26 of the container. The portion 31 is hollow and includes a flat surface 33 serving as a microscope flat slide on which the sediment may be placed for examination after centrifugal separation, Fig. 8. Any overflow of sediment from the surface 33 accumulates in the annular space 35 between the skirt and the portion 31. The surface 33a, Fig. 8a, may be below the edge 30a of the skirt portion 21a so that the depth of the specimen to be examined is kept constant, the specimen on the surface 33a being squeezed by a cover slip 37a until the latter engages the edge 30a. Alternatively, a flat depression may be provided in the surface 33a. The surface 33a may be cross-hatched to facilitate counting of sediment particles or a separate insert with cross-hatching may be used. In one method of testing urine, after centrifugation and decanting of the supernatant liquid, the cap is replaced and the container is shaken vigorously to mix the sediment and the remaining supernatant liquid to produce a suspension of the sediment. Next a drop of the suspension is placed on the slide surface 33 of the cap, Fig. 8 by striking the edge of the tube against the side of the slide. A cover glass may first be placed on the drop before examination. Staining of the sediment may be effected by placing a drop of stain in the annular space 35 in the cap. The cap is replaced on the container which is then shaken to produce thorough mixing, the remainder of the procedure being repeated. In an alternative method, a drop of the suspension may be emptied from the container on to a conventional microscope slide. In a further method, the capped container is shaken in the inverted position so that the sediment suspension accumulates in the space 35 of the cap which is then removed and a drop of the suspension is deposited on a conventional slide. The container may also be used for the separation of cells suspended in water or metal particles suspended in oil.