As the costs of an ELISA development are not generally predictable, we divide our projects into working units. For these units we bind ourselves to a maximum total expense that is exceeded only on the customer's request. The aim of this approach is to provide an optimal cost forecast.

Each working unit will be summarized in a detailed report, which will also include a recommendation for further work. Based on this report, our customer can then decide whether or not to pursue the project. The cost of each working unit is calculated in terms of hours worked. The number and the duration of working units will be determined in discussion with the customer, as will the specifications of the prospective test. Typical working units are:

• Antigen preparation
• Antibody generation / purification
• Conjugate synthesis and purification
• Validation of reagents, showing their fundamental suitability for ELISA, their specificity and the accessible detection range
• Assay-optimisation. This includes the coating procedure, the concentration of reagents, the composition of buffers, assay standardisation and the establishment of a working protocol.
• Assay-validation. This comprises the measurement of defined samples to determine the specificity and sensitivity of the test; analysis of correlation to other test systems, of stability, and of intra- and inter-assay variance. The validated test should be ready for production.

STEFFENS BIOTECHNISCHE ANALYSEN GmbH is licenced to manufacture ELISA test kits for human diagnostic purposes, according to the european iVD directive 98/79/EG.

Instructions for the production of an ELISA test may derive from our own research or, alternatively, can be prescribed by the customer. Production consists mainly of the preparation of the solid phase and of all liquid components. We are willing to make proposals for test kit packs, e.g. outline text for labels and manual, designs for packaging.

Most importantly, the instructions for quality control (QC) and the QC criteria will be determined in close cooperation with our customer. We are flexible enough to deliver productions of prototypes with preliminary packaging. The cost of the production of ELISA test kits depends on numerous factors and will be calculated individually.