Biophysical characterisation of biomolecules and of their interactions in solution as well as on a live cell level represents the main object of our research. Methods include fluorescence and time resolved techniques performed over a wide range of time resolution. Studies by optical spectroscopy are complemented by biocalorimetry (DSC).

Quantitative studies on molecular dynamics on a single molecule level are performed using advanced fluorescence correlation techniques. Among others, these methods are applied on studies of ligand-receptor interactions relevant for hormone regulation and...

Abstract: Performing quantitative, highly sensitive measurements at a single molecule level is often necessary to address specific issues related to complex molecular and...

Abstract: Performing quantitative, highly sensitive measurements at a single molecule level is often necessary to address specific issues related to complex molecular and biochemical systems. For that purpose, we present a technique exploiting both the flexibility of immunoassays as well as the low operating costs and high throughput rates of the fluorescence correlation spectroscopy (FCS) method. That way we have established a quantitative measurement technique providing accurate and flexibly time resolved data of single molecules. Nanomolar changes in adrenocorticotropic hormone (ACTH) levels have been detected in a short time-frame that are caused by fast feedback actions in AtT-20 anterior pituitary glands in vitro. Especially with respect to clinical diagnostic or mathematical modeling this improved FCS setup may be of high relevance in order to accurately quantify the amounts of peptide hormones-such as ACTH-as well as signaling molecules, transcription factors, etc., being involved in intra- and extracellular reaction networks.

Original publication: Puchinger MG, Zarzer CA, Kügler P, Gaubitzer E, Gottfried Köhler (2012). In vitro detection of adrenocorticotropic hormone levels by fluorescence correlation spectroscopy immunoassay for mathematical modeling of glucocorticoid-mediated feedback mechanisms. EURASIP Journal on Bioinformatics and Systems Biology, 2012 2012:17. PMID: 23102048

Abstract:

Biomarkers are essential part of daily medical practice. Currently, biomarkers are being used both for diagnostic and prognostic purposes. There are many...

Abstract:

Biomarkers are essential part of daily medical practice. Currently, biomarkers are being used both for diagnostic and prognostic purposes. There are many approaches e.g. ELISA by which biomarker levels are detected from patient samples. However, all these approaches are laborious, time consuming and expensive. There is therefore a general need for exploring new technique which can overcome these drawbacks. Here, we present a preliminary study for detection of serum biomarkers by fluorescence correlation spectroscopy (FCS) based diagnostic technique. FCS is a technique basically used for spatial and temporal analysis of molecular interactions of extremely low-concentration biomolecules in solution. FCS is able to measure diffusion time of the fluorescent molecules passing through the open detection volume and it can also measure the average number of fluorescent molecules passing through the detection volume. Because diffusion speed is correlated with shape and molecular mass of the fluorescent molecule, this property makes it possible to study the complex formation between a small fluorescently labelled and a large unlabelled molecule. In this preliminary study, we utilize this FCS property for detection of serum biomarker. Further studies on various pathological serum samples are warranted to explore further aspects of this technique.

Original publication: Aamir Shahzad, Martin Knapp, Irene Lang and Gottfried Köhler (2011).The use of Fluorescence Correlation Spectroscopy (FCS) as an alternative biomarker detection technique: A preliminary study. Journal of Cellular and Molecular Medicine. Vol 15, No 12, pp. 2706-2711 PMID: 21306559