Abstract: There are described a novel removable pipette tip and pipette therefor, which provide separation of substances of a liquid within the tip by centrifuging the tip. The tip comprises a liquid-confining cavity disposed about an axis of symmetry, a dispensing aperture, and separating structure spaced along the axis away from the dispensing aperture, for separating one of the liquid substances when the tip is spun about such axis. The pipette is rotatable and either the pipette or the analyzer includes a driver for spinning the pipette tip at high speed.

Abstract: Means are described for positively engaging a key in a keyway in a pipette and its support, to insure that proper dispensing position is maintained and that the pipette stays in the support. Preferably spring means are provided on the key for pressing against the keyway.

Abstract: There is described a package and method of packaging that provide, in inexpensive form, means for adding accurate amounts of one material to another. The package, which can come as a kit to be added to a lyophilizing bottle and stopper, features a portion that is added to the bottle outlet to confine the material that is to be stored separate from the contents of the bottle. That portion includes a plunger preferably constructed to provide a dual function: that of sealing the stopper against the bottle outlet, and of permanently attaching to the stopper to remove it from the bottle when the plunger is moved within the upper portion. Because of its hollow configuration, the plunger can be used to pour off the resulting mixture.

Abstract: There is disclosed a filter and a device positioning the filter between an upper and a lower chamber, particularly useful in an immunoassay. The filter and device are improved in that the membrane comprising the filter is overcoated with at least one water-soluble polymer of a type, a molecular weight, and at a dry-solids coverage effective to create for that membrane an induction time at room temperature of at least about 30 seconds and no greater than about 300 seconds, for a liquid head of pressure of about 6 mm of water.

Abstract: There is disclosed a liquid-collecting compartment that is vented to allow air to escape. The compartment is improved in that a closure member is provided constructed so as to be slidable onto and off of the vent aperture with a force that is between about 0.15 newtons and about 20 newtons. To achieve this, an elastomeric member is provided in the closure member or the wall at the aperture, with selected properties of durometer, cold flow and static coefficient of friction against polystyrene.

Abstract: There are disclosed certain pyrylium salts and a method of making them. The dyes are useful both medicinally in photodynamic therapy and in photoconductive compositions, photoresist and lithographic compositions or optical recording discs. The salts are mixed seleno- or telluropyrylium compounds having a singlet oxygen quantum efficiency of at least 0.005 when exposed as described at wavelengths between about 650 and 1000 nanometers, and a Lewis base anion.

Abstract: In an apparatus for electrophoresis, using a support for a gel and a liquid buffer, a plurality of driving electrodes arrayed in spaced relation to one another so as to contact the medium, and a plurality of sensing electrodes arrayed in spaced relation to one another and the driving electrodes so as to contact the medium. Each sensing electrode is preferably radially inward of and paired with a single one of the driving electrodes. Means are provided respectively for providing electrical potentials to be applied to selected ones of the driving electrodes, for applying the provided potentials, for sensing electrical potentials at selected ones of the sensing electrodes, and for adjusting the applied potentials to maintain the sensed potential at a selected value at a sensing electrode of each pair. The apparatus may be programmably controllable so as to enable an electric field to be modulated in amplitude and direction, as a function of time.

Abstract: There is disclosed a thermal cycling cuvette constructed with an improved sample fluid thermal time constant. The fluid surface-to-volume ratio, and the cuvette thermal path length and thermal resistance of at least one of the walls that provides a major surface of contact, are selected to provide such a thermal time constant that is no greater than about 10 seconds for a cuvette volume no greater than about 200 .mu.l. Also included in the cuvette are means permitting the introduction and removal of liquid into and from the cuvette. A preferred construction permits ready and substantially complete removal of the liquid.

Abstract: An improved test device, useful in conducting reactions, which comprises (a) a well lconfigured to confine temporarily a liquid patient sample admixed with at least one reagent, such as an immunoreagent, to conduct such a reaction, (b) a filter at the bottom of the well with pores effective to pass free, unreacted reagent but not reacted or complexed reagent, and (c) an absorbent material underneath the filter effective to draw off liquid in the well after the reaction. The device further includes (d) a non-absorbent pad underneath the filter, adjacent to the absorbent material, and (e) means for moving the filter and the absorbent material relative to each other, and the filter and the pad relative to each other, between two positions, one in which the filter contacts the non-absorbent pad and the other in which the filter contacts the absorbent material.

Abstract: There is described a stopper remover for automatically removing a stopper in a container, the remover comprising first mechanism for gripping the container against rotation, second mechanism for gripping the stopper, and a drive for rotating the second mechanism about an axis while the second mechanism grips a stopper. The remover features an engaging assembly for frictionally engaging a stopper while the rotating drive rotates in only one direction, the engaging assembly comprising an annular ring and extending from the inside of the ring, a plurality of spikes terminating in points disposed generally in an annular surface inside of the ring and constructed to engage a stopper, the spikes being mounted on the ring so as to be non-radially aligned. The result is that the spikes positively grip the stopper only if the ring is rotated in the one direction, and slip off the stopper when the rotating drive rotates in a direction opposite to the one direction.

Abstract: An envelope holder is described for feeding envelopes through a printer. It comprises a pocket formed from an upper and lower sheet joined together, a window portion of which is removed to allow printing of an envelope held in the pocket. The holder is improved in that the upper sheet has longitudinal edges that extend only a fraction of the length of the lower sheet portion that forms the pocket. That fraction is between about 30% and about 85% of the lower sheet length.

Abstract: There is described an electrophoresis device having a support for a gel plate assembly, and means for clamping such plate assemblies to the support. The support provides a surface that is inclined at an angle of between about 5.degree. and about 10.degree. from the vertical, so that the bottom of the plate is closer to the user than is the top.

Abstract: A catheter is described to provide perfusion while a body vessel is being blocked by the catheter for angioplasty treatment. Intake apertures and ejection apertures are constructed with one-way valves that permit the upstream apertures to only take fluid into the catheter, and the downstream apertures only to eject fluid from the catheter. A pump cooperates with the one-way valves to eject the drawn in aliquot without having to circulate the body fluid outside of the body vessel.

Abstract: There are described the apparatus and a process for using it, wherein a wash station is provided apart from a continuously rotating incubator. Means are provided for moving a test element to the wash station before or in the middle of its incubation, and from the wash station to the incubator after it is washed.

Abstract: A molded article containing an electrical element buried therein has at least two leads, and portions of the leads are left exposed. The article is improved in that all of the leads are left confined within the confines of the article, the exposed portions of the leads being disposed within at least one aperture through the article.Also a molding process for making the article useful as a catcher plate for an ink jet printer. Broadly, the process comprises the steps of placing the portions of the leads to be exposed, each in a groove in a post that is part of the mold, and closing the mold cavity with a closure plate containing an elastomeric material aligned with the post and leads, such elastomeric material having a coefficient of thermal expansion that is greater than that of the material used to make the mold.

Abstract: There is disclosed a pipette and a method of using the pipette in which an active element of the pressurizing system is a bellows within a piston chamber, operated by a motor. To achieve the advantages of the invention, including ease in manufacturing and the ability to actuate a tip ejector, the bellows is mounted so that the outside surface of the sidewall of the bellows, together with the piston chamber, defines the air volume operative on a fluid passageway leading to a disposable tip.

Abstract: A surgical catheter is disclosed, comprising a distal end for advancing into a blood vessel at a single incision remote from occlusions, a proximal end for manipulating the catheter ex vivo, a body portion connecting the two ends, and means adjacent the distal end for cutting away such occlusions while the distal end is far removed from the incision, the cutting means including at least a movable cutting edge. The catheter is improved in that the movable cutting edge is disposed so that it faces rearwardly, towards the body portion. Further there is included means for moving the cutting edge rearwardly to cut tissue or fatty deposits towards the catheter body portion and the remote incision.Such a catheter is used in a surgical method such that the cutting means is activated to cut the fatty deposits only in a rearward direction towards the incision, instead of in an advancing direction.

Abstract: There is disclosed a container for storing a reagent and then for reacting the reagent to produce a signal representative of the presence of an analyte, or of the amount of that analyte. The container is disposable and comprises at least one compartment having an upper portion and a lower portion. The upper portion comprises a stored reagent and means for retaining for observation on an indicator surface a reaction product of such reagent following a reaction of the reagent with a liquid sample. The lower portion includes means for absorbing liquid extracted from the upper portion through the retaining means. The absorbing means is configured with a shape that contacts the confining means only at locations spaced inwardly away from at least two of the side walls of the upper portion, whereby the reaction product of the liquid sample and the reagent is induced to flow into the confining means away from the two side walls to produce a uniform signal.

Abstract: There is disclosed an electrophoresis device comprising a gel plate assembly on a support, and an upper and a lower buffer tank. At least one of such tanks includes means for releasably mounting the at least one tank in liquid contact with the interior of the gel plate assembly and in removable position on the support, the releasable mounting means including a clamp that biases the at least one tank against the support with the gel plate assembly held between the at least one tank and the support.

Abstract: There is disclosed a cuvette constructed with an improved sample fluid thermal time constant, featuring a flexible heat transfer wall. To prevent such wall from deforming under pressure generated at high processing temperatures, thereby reducing heat transfer efficiency, the opposite wall is constructed to have a flexural strength that is sufficiently less than that of the heat transfer wall. This causes flexing to occur in the opposite wall, under pressure, rather than the heat transfer wall.