Becton Dickinson and Company Limited

Sangstat Medical Corporation

Applied Immunesciences, Inc.

Quidel Corporation

Chin-Hai Chang

Philippe J Pouletty

Alex M Saunders

Brian R Clark

Thomas B Okarma

L Bernard Lerch

Methods and compositions are provided for the determination of cross-reactive alleles, where there is no antibody which will specifically distinguish between the two alleles. Particularly, the method employs an antibody which binds to the two alleles bound to a surface, an antibody specific for one of the alleles, a labeled conjugate which binds to a consensus sequence present in both alleles and positive and negative controls. By having an enhanced value where the interfering allele is present as compared to a value for the target allele, one can distinguish between the various alternatives involving the presence or absence of one or both alleles.

Alloantigen enhancement assay

The invention provides for methods and compositions to detect the presence of anti-HLA antibodies, HLA antigen or preformed HLA-containing immune complexes in biological samples. The complement protein Clq is bound to a solid substrate, then mixed with a biological sample containing immune complexes. The immune complexes are preformed, or formed by adding HLA antigens to a biological sample containing antibodies to HLA, or alternatively, by combining a biological sample containing HLA antigens with defined antibodies to HLA. The immune complexes bind to Clq, and are then detected by the addition of a labeled reagent.

Detection of HLA antigen-containing immune complexes

Reactivity between alloantigen and alloantigen-specific ligand, such as HLA and anti-HLA antibody, is detectable in a sample by separating from the sample a portion of a targeted class of ligands (including such ligands complexed with alloantigen) and measuring the amount of alloantigen in such complex containing fractions. In another embodiment of the invention, reactivity between a plurality of samples is detected by measuring soluble alloantigen in at least first and second biological samples and in a mixture of the samples. Since the formation of alloantigen immune-complexes in the mixture alters the physical and immunological behavior of soluble alloantigen, a divergence between the measured and expected concentration of the mixture indicates reactivity.

Detection of soluble alloantigen immune complexes

Methods and compositions for membrane flow-through assays using substrate and enzyme conjugate is described. A preferred method of the present invention comprises providing E. coli alkaline phosphatase (ECAP) conjugate, with additional color enhancement provided by combining lithium salt with the substrate, calcium and/or magnesium salts with the conjugate, and polyalcohol polymers with the conjugate. Color development is further enhanced by spotting tetrazolium dyes, such as the Nitro Blue tetrazolium series, onto the membrane.

Stable alkaline phosphatase compositions with color enhancement and

Compositions and devices are provided for the specific removal of components of plasma in efficient and economical ways. The devices provide for a tortuous path of the plasma through a high surface material to which is bound a binding compound for removal of the fluid component. The devices find particular application with plasma, in diagnosis, therapy, and for production of specific physiologically active materials.

Device for plasma modification--composition and remodeling

Blood derived fluids are subjected to modification resulting in the production of anaphylatoxins. The anaphylatoxins may then be removed by passing the modified blood through silicic acid particles in an amount sufficient to substantially reduce the anaphylatoxins, while still retaining the other blood components and without affecting adversely the use of the blood for the patient.

Plasma processing device with anaphylatoxin remover

A lysing agent and a method for utilizing the lysing agent in the identification and enumeration of cells of a select subclass of leucocytes is provided. The lysing agent includes formaldehyde, an alkali or alkaline earth salt of a weak acid and a polyhydric alcohol.

Lysing agent for analysis of peripheral blood cells

A method for identifying subpopulations of cells of interest without interference from other cells. In the method, a sample of at least three (3) types of cells, including a first and second type of cell which form a subpopulation of cells of interest and a third type of cell which interferes with the identification of said subpopulation, is divided into at least two (2) aliquots. A first antibody which is specific for the third type of interfering cells but not for the subpopulation, is labeled with two (2) fluorochromes, each of the fluorochromes having distinct emission spectra. The labeled first antibody is then added to a first one of the sample aliquots so as to label the third type of cells with the first antibody. A first analysis is performed by analyzing each cell to determine the fluorescence emitted and to count the third type of cells so as to distinguish the third type of cells from the subpopulation. The information obtained from the first analysis is retained for subsequent use. The above steps are repeated for the subpopulation of cells of interest and a second analysis is obtained. The retained information from the first analysis is used to remove the effect of the third type of interfering cells and to provide a direct proportional analysis of the first and second types of cells in the subpopulation of cells of interest.

Growing community of inventors

Los Altos, CA, United States of America

Chin-Hai Chang