Lab-on-a-chip technology for clinical diagnostics: The fertility chip

In the 1990s the term micro total analysis systems (μTAS) was introduced to describe a complete microsystem which integrates sample handling, analysis and detection into a single device, also called Lab-on-a-Chip (LOC) device (1). The LOC concept defines the scaling down of a single or multiple lab processes into a chip format with dimensions as small as a stamp. Scaling down offers many advantages, such as less sample, reagent and waste volumes, faster analysis, integration of many analytical processes within one device, lower cost, to name a few, but first of all an easy handling. These advantages meet the actual demands of clinical laboratories, which are dealing with an increasing workload and decreased funding. Our group showed previously these advantages of the LOC technology for blood electrolyte determinations in clinical diagnostics (2). Furthermore, microfluidic dimensions (10 - 100 μm) equal the size of cells, making these devices very suitable for the analysis of many different biochemical processes even on a single-cell level. Hence, there are many reasons why microtechnology is advantageous compared to existing conventional analysis methods, especially in the case of cellular based assays, to understand how cells react in a certain environment, to a certain drug or in contact with other cell types. Different cell manipulation methods (e.g. sorting, detachment, staining, fixing, lysis) can be integrated on one chip, less sample is needed ideally when only a few cells are available (e.g., primary cells) and the dimensions favour single-cell analysis. Furthermore, optical detection techniques can be automated and in some cases be replaced by electrical on-chip detection methods. Moreover, development of cell arrays, which are analogous to DNA or protein arrays, offer the possibility for high-throughput screening. Recent technological developments enable detailed cellular studies, defining a new concept: Lab-in-a-Cell. In this concept the cell is used as a laboratory to perform complex biological operations. Micro- and even nanotechnological tools are employed to access and analyse this laboratory and interface it with the outside world. In the present manuscript we will summarize our recent efforts to demonstrate the advantages of LOC technology to study cells for clinical diagnostics by working on a fertility chip as an example.