Abstract: A FireNet security system in which trustworthy networks, called BlackNets, each comprising One (1) or more client computers, are protected by FireBreaks against attacks from untrustworthy networks, called RedNets. All incoming transactions from the RedNet are examined by the FireBreak to determine if they violate any of a plurality of protection rules stored in a local protection rules database. Any transaction found to be in violation is discarded. Valid transactions are forwarded to the BlackNet. If an otherwise valid transaction is found to be suspicious, the FireBreak will forward to a FireNet Server relevant information relating to that transaction. If the FireNet Server verifies that the transaction is indeed part of an attack, the FireNet Server will create new protection rules suitable to defend against the newly identified source or strategy of attack. Periodically, all FireBreaks in the FireNet system will transfer, directly or indirectly, all new rules.

Abstract: The present invention provides a reagent for extracting lead ions from a variety of biological matrices such as human whole blood that has been anticoagulated with either heparin or EDTA, and lyophilized human blood and bovine EDTA whole blood. The released lead is measured in situ with a calorimetric porphyrin reagent without further manipulation of the supernatant. The lead ion releasing reagent can be used in conjunction with a variety of assay formats for the determination of lead in various biological fluids.

Abstract: The present invention provides a reagent for extracting lead ions from a variety of biological matrices such as human whole blood that has been anticoagulated with either heparin or EDTA, and lyophilized human blood and bovine EDTA whole blood. The released lead is measured in situ with a colorimetric porphyrin reagent without further manipulation of the supernatant. The lead ion releasing reagent can be used in conjunction with a variety of assay formats for the determination of lead in various biological fluids.

Abstract: The present invention relates to a method for the determination of polyvalent metal ions using a sandwich aggregation assay. One or more chelating agents capable of forming at least 2:1 or higher ratio stoichiometry complexes with polyvalent metal ions are attached to a suitable carrier such as latex particles through covalent bonds or by non-covalent interactions, such as hydophobic interactions. Upon complexation with the metal ions, the carriers of the complexing agent aggregate, causing an increase in light absorbance or light scattering which is proportional to the concentration of metal ions in the test sample. The measurement of the light absorbance or light scattering by a suitable instrument, such as a spectrophotometer or nephelometer provides a means for measuring the concentration of metal ions.