Molecular Biotechnology

Methods

Compound Screening in vitro

Activation of a GPCR by different ligands
© Fraunhofer IZI
Activation of a GPCR by different ligands.

Efficacy

Permanent cell cultures are used for efficacy testing of novel compounds. Assays specific for the investigated target proteins are applied. Aim is the selection of the most potent compounds.

 

Determination of cytotoxicity for 2 compounds (A and B) using a human hepatocyte cell line
© Fraunhofer IZI
Determination of cytotoxicity for 2 compounds (A and B) using a human hepatocyte cell line.

Toxicity

Cytotoxic and proliferative effects of novel compounds are screened on mammalian cell lines. > 100 cell lines are available for screening. Due to their pivotal role in drug metabolism, all compounds are tested on permanent human hepatocytes.

Apparent permeability coefficient of selected molecules
© Fraunhofer IZI
Apparent permeability coefficient of selected molecules.

Transport

For the prediction of bioavailability in animal models, compounds are tested on an epithelial cell-derived transport model. The applied mammalian cells are human colorectal adenocarcinoma cell line, CaCo-2. Analysis is performed by LC-MS. The apparent permeability coefficient (Papp) is used to estimate bioavailability.

Cell culture of Iba1-positive primary murine microglia cells
© Fraunhofer IZI
Cell culture of Iba1-positive primary murine microglia cells.
Cell culture of GFAP-positive primary murine glia cells
© Fraunhofer IZI
Cell culture of GFAP-positive primary murine glia cells.

Primary cell models

The Molecular Biotechnology Unit has a longstanding expertise in experimental research using primary cells of the central nervous system.

For the prediction of bioavailability in animal models, compounds are tested on an epithelial cell-derived transport model. The applied mammalian cells are human colorectal adenocarcinoma cell line, CaCo-2. Analysis is performed by LC-MS. The apparent permeability coefficient (Papp) is used to estimate bioavailability.

Phenotyping transgenic mouse models

8 x PhenoMaster-System (TSE-Systems)
© Fraunhofer IZI
8 x PhenoMaster-System (TSE-Systems).
IntelliCage (NewBehavior) for automated behavior screening in groups
© Fraunhofer IZI
IntelliCage (NewBehavior) for automated behavior screening in groups.

Phenotyping of transgenic mouse models follows the SHIRPA protocol. It is divided into primary, secondary and tertiary screen. Comprehensive test batteries for evaluating animal health and specific functions, e.g. motor coordination, cognition and emotion are available. Focus is on automated home cage observation to minimize the contact of humans with the laboratory mice.

Histology

Hematoxylin/Oil-Red staining of a plaque in the arterial wall of an atherosclerotic rabbit
© Fraunhofer IZI
Hematoxylin/Oil-Red staining of a plaque in the arterial wall of an atherosclerotic rabbit.
Thioflavin S-positive deposits (green) in hippocampus of an Alzheimer mouse model
© Fraunhofer IZI
Thioflavin S-positive deposits (green) in hippocampus of an Alzheimer mouse model.

To investigate disease-relevant pathologic alterations, a number of cutting and staining techniques are available.

Pharmacology

Concentration of a compound in the circulation after oral exposure
© Fraunhofer IZI
Concentration of a compound in the circulation after oral exposure.

The determination of pharmacological parameters, e.g. bioavailability and plasma half-life, is done in-house using catheterized rats. Experiments are performed after extensive testing of compounds in isolated cell cultures and after allowance by the local animal well-fare committee. For measuring compound levels in body fluids, LC-MS-based methods are available.