Abstract: A multilayer dry immunoassay element comprising 1) a spreading layer having a sample application area and a signal read area and 2) a separate receptor layer residing on 3) a radiation-transmissive support characterized in that the spreading layer contains a light absorbing material.

Abstract: The Thermus aquaticus gene encoding a thermostable DNA polymerase (Taq Pol) is altered in the N-terminus-encoding region to provide mutant genes with improved expression in E. coli.

Abstract: A spectrophotometric assay for the detection of acetaminophen in aqueous fluids can be carried out with a dry analytical element. The element comprises a support having thereon one or more reagent layers containing a first enzyme, aryl acylamidase, to cleave the amide bond of acetaminophen to produce p-aminophenol; a second enzyme, ascorbic acid oxidase, to oxidize the p-aminophenol so that it couples to a water soluble coupling agent to form a dye that is read at 670 nm. The assay is precise, accurate on serum and plasma samples, and relatively free from significant interferences. The element also allows measurement over a broad dynamic range.

Abstract: The present invention provides admixtures and methods for PCR amplification of a target nucleic acid in which amplification efficiency is increased by including an antibody specific for a polymerization agent and at least one of an exonuclease and a glycosylase in the PCR reaction mix. Kits for amplification of a target nucleic acid are also provided.

Abstract: A dry analytical element has been prepared for the assay of prostatic acid phosphatase at a pH of from about 3 to about 6.5. The element can be a single porous spreading zone or a multilayer structure. Within the element is a relatively nonhygroscopic aromatic phosphate substrate for the analyte which produces a phenol reaction product. This product is reacted with a diazonium or tetrazolium salt, also in the element, to produce a chromophore for detection. A buffer in the element maintains it at the proper pH during the assay.

Abstract: The present invention provides a novel dry analytical element for determination of an analyte in a fluid sample in thin film immunoassay, particularly chemiluminescence, fluorescence and colorimetry immunoassay. There is provided an analytical element comprising a support member, a reagent matrix comprised of at least one layer of a porous material carried on the support member, the matrix including a read area, an absorbent material in contact with the matrix, and light absorbing or reflecting means integral to the absorbent material and/or positioned between the absorbant material and the read area for absorbing or blocking background signal generated by washed, removed label and other interferents from outside the read area prior to it moving back into the read area. The analytical element can comprises a cover depending on the type of immunoassay to be conducted.

Abstract: An apparatus and a related method for uniformly transferring a liquid material to a test slide element in which a transfer element having a liquid supporting surface area approximately equal to the surface area subtended by the test volume of the test slide element is brought into direct contact with the test element surface so that the liquid is distributed all at once thereto.

Abstract: The present invention provides a more accurate risk assessment of antenatal screening results because the maternal age of the patient is considered in evaluating the results from various common screening markers, and especially the results from UE determinations.

Abstract: A dry immunoassay analytical element, for assaying a ligand, comprising in the following order:(a) a layer containing a labeled ligand;(b) a spreading layer;(c) a receptor layer containing a fixed concentration of an immobilized receptor for the labeled ligand and the receptor is i) covalently bonded to polymeric beads having a diameter in the range of 0.1 to 5 .mu.m and ii) dispersed in a polymeric binder and(d) a support;characterized in that the spreading layer contains a water soluble polymer containing vanadium IV (V.sup.+4) ions.