In the Biochemical Laboratory of the Department of Biological and Clinical Psychology, analytes can be determined from the body fluids blood, saliva and urine, as well as from cell culture supernatants, using a wide variety of methods.

Free cortisol in saliva - DELFIA

More than 30 years ago, the development of a highly specific method for the analysis of cortisol in saliva (Dressendörfer et al., 1992) laid the foundation for a large number of studies on the responsiveness of the hypothalamic-pituitary-adrenocortical (HPA) axis.  In many psychobiological studies of HPA axis activity, cortisol is measured as its end product. Most of the cortisol in serum is bound to transport proteins and thus is not biologically active. Only the smaller fraction of free cortisol finds passage into saliva; correlations between concentrations in saliva and serum are very high ~r=.90.

We use a highly specific DELFIA immunoassay to determine the concentration of free cortisol in saliva. DELFIA stands for "Dissociation-Enhanced Lanthanide Fluorescent Immunoassay" and is a highly sensitive and specific analytical method used in various bioanalytical and diagnostic tests. DELFIA uses lanthanide chelates (rare earths) as a fluorescent marker to enhance the detection of specific molecules or markers such as antibodies, antigens or other biological molecules, in our case cortisol. Key features of DELFIA include the ability to provide a low background signal, high sensitivity and a wide dynamic range.

Alpha amylase in saliva

Alpha amylase is an enzyme found in various biological fluids, including saliva. It plays an important role in the digestive system by breaking down starch and glycogen into simpler sugars, especially maltose. Alpha-amylase is therefore involved in the digestion of carbohydrates. There are two main sources of alpha-amylase in the human body: the pancreas (pancreatic amylase) and the salivary glands (salivary amylase). The concentration of alpha-amylase in saliva can serve as an indirect marker of stress responses. During acute stress, the release of alpha-amylase in saliva increases. Therefore, this measurement is often used in psychology and stress research to study the physiological response to stressful situations.

A colorimetric assay using 2-chloro-4-nitrophenyl-aD maltrotrioside (CNP-G3) as substrate is used to determine a-amylase activity in saliva samples. Amylase activity cleaves the color-producing CNP group and displays it as an increase in absorbance. The color intensity of the formed p-nitrophenol (CNG) is directly proportional to the amylase activity and is measured photometrically.

Our service

Numerous research groups in Germany and abroad use the competence of our laboratory.
If you have any questions regarding possible analyses and conditions, please do not hesitate to contact our team at cortlabuni-trierde

We analyze the following hormones,enzymes and immune parameters:

• Adrenocorticotropic hormone (ACTH)
• Alpha-amylase
• Cortisol
• Dehydroepiandosterone (DHEA bzw. DHEA-S)
• Ghrelin
• Melatonin
• Immune globuline
• Insulin
• Interferone
• Interleukine (IL-2, IL-6, …)
• Catecholamines
• Leptin
• Estrogene
• Progesterone
• Prolaktin
• PYY
• Testosterone
• TNF and others

• Prof. Dr. Gregor Domes
• Dr. rer. nat. Andrea Gierens
• Annemie Fritzen
• Nicole Reinert
• Sandra Scholtes