Xenopus laevis, stage V oocytes

Treatment exposure modality:	Temporary immersion
Efficacy type:	Current amplitude (A or %)
Stock solution:	20 mM in DMSO or H₂O
Volume / datapoint:	1 μL (triplicates)
Starting concentration:	10 μM

In Brief:

Cells expressing significant current evoked by a brief agonist pulse (e.g. acetylcholine) are tested for their response to test compounds using a protocol of pre- and co-application of the compound.

We use a pre-application of 45 s and co-application of 10 s with the natural agonist. The advantage of this screening protocol is the possibility to reveal agonistic effects during the pre-application and modulatory or inhibitory effects of the compound during the co-application. The percentage of agonism, positive modulation (PAM), antagonism, desensitization or recovery is calculated compared to the reference natural agonist peak current.

Definitions:

To ensure flawless communication, the following definition section introduces the vocabulary used at INVENesis. You will find this vocabulary on our quotes, raw data files, processed data files, preliminary and final reports. Open the Lexicon below.

Lexicon

Assay Preparation:

Test plate: microplate in which an assay is run
Mother plate: microplate containing stock solutions
Stock solution: solution contained in mother plates out of which dilutions will be made
Daugher plate: microplate containing solutions used to treat test plates, usually dilution series

Type of Assays:

Organism-based assays : functional assay measuring a phenotypic response on a whole organism. Typically, motility, development, deterrency, repellency.
Electrophysiology assays: functional assay measuring the electrical respons of a receptor or an organ to a stimulus
Stock solution: solution contained in mother plates out of which dilutions will be made
Daugher plate: microplate containing solutions used to treat test plates, usually dilution series

Treatment exposure modalities:

Treatment modalities relate to the way the treatment is applied. Different treatment modalities help define how an active ingredient is most susceptible to act in a field case. Some compounds are more active when eaten, others are more active when applied externally on an organism. The following vocabulary is used in the list of assays:

Tarsal:

Tarsal: individuals are allowed to walk on surfaces treated with a formulated active ingredient.
Tarsal with choice: only a proportion of the surface accessible to individuals is treated.
Tarsal without choice: the whole surface accessible to individuals is treated so that individuals are unable to rest on untreated surfaces.

Topical:

Topical: direct application of a known amount of formulated active ingredient on a single individual

Oral:

Oral: voluntary feeding on medium treated with a formulated active ingredient.
Oral with choice: both a treated and an untreated medium are provided.
Oral without choice: only one treated medium is provided.

Immersion:

Immersion: individuals are immersed in a treated formulation.
Permanent Immersion: individuals are immersed for the whole duration of the assay.
Temporary Immersion: the treatment is removed after temporary immersion of individuals.