Boehringer Mannheim Gmbh

Roche Diagnostics Gmbh

David J Ledden

Scott J Eisenbeis

David R Moorman

Mark Krevolin

Sophie J Boguslawski

Brian A Heald

David D Webster

Harvey B Buck

Scott Clark

Michael J Kinch

Christopher P Bryant

The invention relates to a process for making a test element, such as an analytical test element. Compositions of matter, such as analyte specific receptors, are treated to carry a charge. These are then applied to test carriers treated to carry a charge opposite that of the composition of matter. Interaction of charge fixes the composition of matter to the test element.

Process for preparing test elements

Muteins of enzyme acceptor polypeptide fragments of .beta.-galactosidase are provided which exhibit substantially increased kinetic complementation activity with no significant loss in stability. A preferred enzyme acceptor fragment has an amino acid other than cysteine located at position 500 of the natural sequence. An especially preferred substitution is serine or valine. Other preferred muteins have an amino acid other than methionine located at position 443, with leucine being especially preferred, or an amino acid other than cysteine at position 76, with leucine being an especially preferred substitution. Also provided are methods for producing the novel muteins, reagent compositions comprising the novel muteins, and immunoassay methods for determining an analyte in which the novel mutein recombines with an enzyme donor polypeptide fragment to form enzymatically active .beta.-galactosidase.

Muteins of .beta.-galactosidase fragments having increased activity

A mutein of an enzyme acceptor polypeptide fragment of .beta.-galactosidase which is resistant to oxidation is provided. The enzyme acceptor fragment has an amino acid other than cysteine located at position 602 of the natural sequence. An especially preferred substitution is serine. Also provided are a method for producing the novel mutein, a reagent composition comprising the novel mutein, and an immunoassay method for determining an analyte in which the novel mutein recombines with an enzyme donor polypeptide fragment to form enzymatically active .beta.-galactosidase.

Oxidation-resistant muteins of .beta.-galactosidase fragments

The invention is an apparatus useful in carrying out an analytical assay. The apparatus has a positive and negative control, as well as a site for determining the presence, amount, or lack of an analyte in a sample.

Analytical test apparatus with on board negative and positive control

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Indianapolis, IN, United States of America

David J Ledden