Abstract: A system and method (10) for deriving access codes for billing customers includes a load process (12) receiving a set of system attributes (20) and using at least one of the system attributes (20) for looking up in at least one lookup table (16, 18, 22, 24) for an access code and at least one formula value, and further storing the access code and at least one formula value in an access code lookup table (26, 28). The system (10) further includes a derivation process (14) which receives a specification of values for the set of system attributes from a billing record (30), uses the specification of values for looking up in the at least one lookup table (16, 18, 22, 24) for a derivation formula, uses the derivation formula for looking up in the billing record (30) for an attribute value, and further uses the attribute value for comparing with the formula value stored in the access code lookup table (26, 28).

Abstract: The hydrogel-forming polymers are used as absorbents for collecting and concentrating solutions. A solution to be concentrated can be contained in a dialysis membrane, with the hydrogel-forming polymer, or mixture thereof, on the outer surface of the membrane. A hydrogel-forming polymer can be added directly to the solution to be concentrated and the resulting concentrate separated from the gel by filtration of decanting. A hydrogel-forming polymer can be placed in a container formed of porous material and the container can be added to the solution to be concentrated and physically removed after concentration has occurred. Hydrogel-forming polymer can be used as a liquid collection in diagnostic membrane assay cartridges.

Abstract: An improved, copolymer-based immunoassay system, method, and apparatus is highly sensitive and effective in accurately measuring extremely low concentrations, such as 10.sup.-6 to 10.sup.-12 grams per milliliter, of biologically active substances, such as monoclonal or polyclonal antibodies and antigens, cancer markers, proteins, bacteria, viruses, therapeutic drugs, drugs of abuse, and food and water contaminants in fluid samples. The system requires no sample preparation, and is reliable, easy to use, sufficiently low in cost to be readily usable in doctors' offices, small labs, and other low-volume facilities, but is also readily adaptable to hospital and high-volume use. The new system, method, and apparatus for agglutination immunoassay systems includes novel and coordinated carrier particle technology, light application and measurement and chemistry, coacting to provide the multiple advantages of simplicity and accuracy in use, and extreme sensitivity in application, in quantifying immunoassays.