Abstract: An electro-mechanical variable fluid flow restrictor includes a support having a passage and a seal surface, a deformable seal that is engageable with the seal surface, and a bias member for exerting an electronically controlled variable bias against the deformable seal. The seal surface includes channels formed in its surface that extend beneath the deformable seal. The bias member can exert a bias sufficient to cause the deformable seal to fill the channels, preventing fluid flow through the channels. When the bias member decreases the bias against the deformable seal, the deformable seal gradually moves out of the channels, allowing fluid flow through the channels, and through the passage in a flow control. The deformable seal does not need to separate from the seal surface to allow fluid flow. Instead, fluid flows through the small, controlled flow areas created when the deformable seal withdraws from the channels.

Abstract: The present invention discloses a novel procedure of removing high abundance proteins (HAPs) from a test sample without the concurrent removal of low abundance proteins (LAPs) that are bound to the HAPs in the test sample. The procedure therefore allows the accurate detection of LAPs without the interference from the HAPs in the test sample. Specifically, the present invention provides methods for detecting LAPs in a test sample by treating the test sample with a proteolytic agent to release HAP-bound LAPs from the HAPs by fragmenting both HAPs and LAPs, removing the HAP fragments from the test sample, analyzing the LAP fragments, and identifying the LAPs in the test sample based on the characteristics of the LAP fragments. The present invention is most useful for the identification of LAPs that are bound to the HAPs in the test sample and are otherwise hard to separate from the HAPs.

Abstract: A device for performing sample acquisition and introduction of a selectable quantity of the acquired sample to associated device such as an analytical instrument.

Abstract: A plurality of different liquid solutions are connected to an input of a pump system having at least two displacement chambers and in a manner to control the proportions of each constituent that are taken into each chamber during its intake stroke. The outputs of the chambers are connected to a common liquid output. The chambers are driven by independently controllable motors so that the discharge stroke may be chosen to have some parameters, such as speed profile and duration, that are different than during the intake stroke. As a result, both chambers may simultaneously discharge liquid through the common output, if desired. The proportion of constituents may be made different each time one of the chambers is filled, so the simultaneous discharge of the chambers allows a gradual, carefully controlled change from the mixture of one chamber to that of the other.