Assuming a molecular weight of 150 kDa per antibody and taking the Avogadro constant of 6 1023mol1, it can be concluded that the amount of antibody/spot under the given assumptions is ~7

Assuming a molecular weight of 150 kDa per antibody and taking the Avogadro constant of 6 1023mol1, it can be concluded that the amount of antibody/spot under the given assumptions is ~7.2 105,i.e., a loading of ~18% of a theoretical dense antibody monolayer. step towards real sample studies, a proof of principle of cytokine detection has been established. Keywords:microarray, protein, antibody, cytokines, spotting, hydrogel, biosensor, fluorescence readout == 1. Introduction == Breath analysis is an interesting and motivating field of research; most recently, it has been found that dogs can smell lung cancer with high Combretastatin A4 probability if trained accordingly [1]. Furthermore, lung diseases Combretastatin A4 like asthma and chronic obstructive pulmonary disease (COPD) show similar somatic symptoms: the airways are inflamed but different medication is required. To distinguish between the diseases, classical diagnostic methods like imaging, spirometry, analysis of bronchoalveolar lavage (BAL), and invasive bronchoscopy are currently applied [2,3,4]. The vision for tomorrow, however, will be as in many medical fields the point-of-need diagnosis, a noninvasive breath analysis in order to spare patients invasive examinations, to increase the specificity of analysis, and to reduce costs. Critical high concentrations of nitrogen monoxide (NO) in breath, a potential marker for asthma, are already detected by chemical gas sensors, but the gaseous fraction of the breath varies strongly depending on personal habits [5,6]. On the other hand, and similar to other body fluids, like blood, urine, and saliva, monitoring of the cytokine pattern in exhaled breath condensate (EBC) can contribute to the identification and diagnosis of diseases [7,8,9,10,11]. Depending on the kind of disease, the body reacts with a certain distinct immune response, Combretastatin A4 and thus different cytokines are present in specific amounts and different cytokine patterns are characteristic, as described for COPD and asthma in Barneset al.[8]. The challenge of EBC analysis will be that the characteristic cytokines are only present in very low concentrations (Rabbit Polyclonal to Bcl-6 Especially 3D polymer/hydrogel modified surfaces or porous nitrocellulose surfaces are often used as substrates in the field of protein microarrays [14]. There are fast test kit immunoassays on the market,i.e., antibody-based assays, which are very well established for diagnostics, giving a fast yes/no answer due to a well-established and validated biomarker. Low analyte concentrations are rarely detected with these immunoassays; however, this is not a must for e.g., pregnancy tests, borreliosis Combretastatin A4 tests, and many others. For example, the hormone human chorionic gonadotropin (hCG) in urine, indicating a pregnancy, is detected in the ng/mL range. In a biochemical laboratory, however, protein microarrays for diagnostic purposes are still not.