Apparatus including a sample petter tube for obtaining reproducible liquid samples of small volume
AssigneeV-Tech, Inc.
InventorJames E. Parker
Life of this patent
Estimating the term…
Abstract
The disclosure teaches a pipette or petter tube and a system using the pipette to obtain reproducible liquid samples of known small volume. The pipette has an elongate body with one end adapted to be removably engaged by an aspiration device and the other end which is closed is adapted to contact a surface. The body has a spherical portion proximate the closed end. At least one aperture penetrates the wall of the spherical portion. When the petter tube is used in conjunction with a hollow tube having a known volume and of such size that the closed end of the pipette contacts the bottom of the tube a quantity of liquid can be aspirated from the tube leaving only a small predetermined volume behind.
Claims6
In an apparatus for preparing a liquid sample of reproducible, small volume comprising, in combination, a test tube having a bottom and an external aspirating means, the improvement wherein the apparatus further comprises:
- a molded unitary sample petter tube comprising:
- (a) a main body portion having an upper end open to the atmosphere and adapted to sealingly engage with said external aspirating means;
- (b) a closed lower end having a pedestal base adapted to be supported by the bottom of said test tube;
- (c) a substantially hollow spherical chamber proximate to said closed lower end, with external wall surfaces of said substantially hollow spherical chamber being spaced from internal wall surfaces of said test tube at its closest distance by about 0.003" to about 0.006" when said closed lower end is supported on the bottom of said test tube whereby said sample petter tube loosely fits within said test tube for ready insertion and removal therefrom;
- and
- (d) a fluid opening provided in said substantially hollow spherical chamber, said fluid opening being spaced from a lowermost extremity of said closed lower end by a finite distance and being in fluid communication with said open upper end of said sample petter tube, whereby when said closed lower end is supported on the bottom of said test tube and said external aspirating means is sealingly engaged to the open upper end of said sample petter tube, all liquid in the test tube above said fluid opening may be removed to leave a defined volume of liquid sample at the bottom of the test tube below the fluid opening.
Dependencies are inferred from the claim text.