Abstract: In a device for the extraction of capillary blood including a capillary open at both ends and being of a predetermined volume, having a capillary effect at least at the front end thereof, a holder is integrally connected to said capillary which is provided with one or more windows.For avoiding dosage errors, a closure pin for the rear end of the capillary or in a modification a rear transverse wall having one or more air exit apertures is provided.

Abstract: A blood-sampling device consisting of a cylindrical tube with a plunger therein, which is closed by an elastomeric stopper which can be pierced by the rear end of a two-ended cannula, the other end of which is intended to be introduced into a vein, whereas the cannula is disposed within a tubular guide sleeve which can be pushed over the front end of the cylindrical tube.

Abstract: A capillary receptacle for the extraction and storage of blood, which receptacle features the improvement that an insert is provided for the receptacle, said insert having a cylindrical main portion inserted into the opening portion of the receptacle and a short funnel-shaped portion adjacent thereto, the tip of which has such a small inner diameter that blood externally thereof is drawn in by capillary action, whereas the main portion has such a large inner diameter that the entering blood is able to freely flow off.

Abstract: A device for the extraction of blood, comprising a cylindrical receiving container, a piston air-tightly guided and shiftable therein and a connecting socket for a cannula at one end of the container, wherein the cylindrical container has an opening in the wall at the end remote from the connecting socket for drawing the air out of this portion of the container, and a suction device for a slow and uniform drawing-off of air connected by a connecting hose with the said opening in the wall of the container. The piston is moved away from the connecting socket and in the direction of the opening when and as long as the suction device is drawing-off the air from the container.

Abstract: An agent for facilitating the counting of thrombocytes in blood samples in the presence of erythrocytes, comprises an aqueous solution of mercuric chloride in a concentration of between 1.2 and 4.0 g/l. The pH of this solution is adjusted to 1.5 to 4.8, preferably by the addition of hydrochloric acid or nitric acid or mercuric nitrate. 2 mls of this solution is mixed with 20 .mu.l of the blood to be tested. The erythrocytes are decolored in this solution and the thrombocytes become more brilliant in the microscopic image so that they are relatively easy to count.

Abstract: This invention relates to a suction pipette comprising, a first piston located within a cylinder and connected to a first hollow, cylindrical piston rod and a second piston located within the first hollow, cylindrical piston rod and connected to a second piston rod such that small doses of fluid may be delivered accurately from the fluid contained within the pipette.

Abstract: Devices for extracting blood which comprises a cylinder having at one end a removable closure member carrying a connection piece for a cannula and an end wall at the other end. A piston is guided in the cylinder in an air-tight manner and a piston rod guided in a central bore in the end wall is releasably attached to an extension of the piston. The end wall forms a rigid stop for the retracted piston and an annular sleeve concentrically surrounding the central bore in the end wall serves for the purpose of receiving and retaining the piston extension, the space between a piston seal and the zone of contact between the extension and annular sleeve being vented when the piston is in its retracted state.

Abstract: A vessel is provided for receiving a small quantity of a liquid to be observed optically. The vessel has a body provided with four upstanding side walls of which two opposite walls are transparent and optically true and are intended to lie in the optical path. The other two walls are much closer together so as to reduce the interior volume of the vessel and are provided with external vertical ribs so as to impart a generally square external configuration to the vessel. A U-shaped thermally conductive body is disposed with its bridge portion beneath the bottom of the vessel body and with its limbs upstanding between the ribs and in thermal contact with said other side walls. The vessel can be secured in position by means of the bridge piece which may be of dovetail shape or may be magnetic or provided with a permanent magnet.

Abstract: The invention relates to a filter device for separating blood fractions into a specifically heavier non-filtratable and a specifically lighter filtratable fraction, characterized by a piston of a soft resilient material, preferably a thermoplastic material, associated with a cylindrical vessel and adapted for airtight sliding movement therein, said piston containing a filter permeable for the specifically lighter fraction but impermeable for the specifically heavier fraction and having at the top side a constricted neck with a flaring upper opening.

Abstract: A pneumatic apparatus is employed to automatically load blood extracting devices. The apparatus includes a cylinder and a piston slidably receivable therein. The piston is connected to a casing or housing which supports a blood extracting device. The cylinder may be partially evacuated by forcing it into the housing. Once evacuated the cylinder is maintained in the biased position by a locking lever. The cylinder may be connected either to a blood receiving vessel or to a piston receivable within the blood receiving vessel through which the blood may be extracted. In order to extract blood the extracting device is first positioned in the vein of a patient in the conventional manner. The locking lever is then released and the partial vacuum within the cylinder causes the plunger within the blood receiving vessel to draw blood inwardly. A check valve and parallel channel arrangement in the plug at one end of the cylinder serves to slow and control the rate at which the blood is extracted.