ATP-based Luminescence in the Absence of Cytokines Measured in Cell-Based System Using Plate Reader - 2061-06_Inhibitor_Dose_DryPowder_Activity
This is a counter-screen to test compounds for ATP-based luminescence in the absence of cytokines. Cells will be treated with compounds at various doses for 48 hours. The cells will not be treated with cytokines. While perhaps interesting in another context, compounds that elevate ATP levels in INS-1E cells under basal conditions are not suitable as probes in this assay. Further, compounds that suppress cytokine-induced beta-cell apoptosis but are toxic in their own right are similarly unattractive. ..more
BioActive Compounds: 2
Depositor Specified Assays
INS1E, cytotoxicity, Cell titer glo, cellular ATP
This is a counter-screen to test compounds for ATP-based luminescence in the absence of cytokines. Cells will be treated with compounds at various doses for 48 hours. The cells will not be treated with cytokines. While perhaps interesting in another context, compounds that elevate ATP levels in INS-1E cells under basal conditions are not suitable as probes in this assay. Further, compounds that suppress cytokine-induced beta-cell apoptosis but are toxic in their own right are similarly unattractive.
Day 0: Collect cells and generate single cell suspension by trypsinization and passing through sterile 40 micron cell strainer (Falcon). Seed 8,000 cells/well of INS-1E rat beta-cell line in 30 uL media using white, opaque, bar coded, 384-well Corning 8867 plates; incubate at 37 degrees C overnight
Day 1: Add 10 uL medium with cytokine cocktail to each well using the Combi. Pin transfer compounds to plates right after the addition of cyokines with 100 nL head and transfer 100 nL compound. Positive control added by double pinning plates.
Day 3: Add 20 uL Cell titer-Glo reagent to plates.
Agitate gently for 15 seconds to maximize cell lysis. Incubate 8 minutes.
Use Envision to read plate luminescence with standard luminescence parameters.
PRESENCE OF CONTROLS: Neutral control wells (NC) were included on every plate.
EXPECTED OUTCOME: Active compounds result in decreasing readout signal.
ACTIVE CONCENTRATION LIMIT:
For each sample, the highest valid tested concentration (HVC) was determined and the active concentration limit (AC_limit) was set to equal (10)(HVC).
The raw signals of the plate wells were normalized using the 'Neutral Controls' method in Genedata Assay Analyzer (v7.0.3):
The median raw signal of the intraplate neutral controls (NC) is set to a normalized activity value of 0.
A normalized activity value of 100 is defined as (2)(NC).
A normalized activity value of -50 is defined as (0.5)(NC).
Experimental wells values were scaled to this range.
PATTERN CORRECTION: No plate pattern correction algorithm from Genedata Condoseo (v.7.0.3) was applied.
MEASUREMENT USED TO DETERMINE ACTIVE CONCENTRATION(AC): AC50
AC values were calculated using the curve fitting strategies in Genedata Screener Condoseo (7.0.3).
AC values were calculated up to the active concentration limit described for each sample.
Activity_Outcome = 1 (inactive) when:
a) curve fit is constant where activity is > -30% and < 30% at all tested concentrations, or
b) AC > AC_limit, or
c) compound shows activity but in a direction opposite to the expected outcome
in these cases, values describing curve fitting parameters (Sinf, S0, Hill Slope, log_AC50, log_AC50_SE) are set to null
Activity_Outcome = 2 (active) when:
AC <= AC_limit
Activity_Outcome = 3 (inconclusive) when:
a) Curve fitting strategy resulted in a constant fit with activity >= -70% but <= -30%, or
b) The fit was not valid due to poor fit quality.
PUBCHEM_ACTIVITY_SCORE = 0 when PUBCHEM_ACTIVITY_OUTCOME = 1 (inactive) or 3 (inconclusive)
PUBCHEM_ACTIVITY_SCORE = (-10)[Log(AC)], where AC is in molar, when PUBCHEM_ACTIVITY_OUTCOME = 2 (active)
Scores relate to AC in this manner:
120 = 1 pM
90 = 1 nM
60 = 1 uM
30 = 1 mM
0 = 1 M
PUBCHEM_ACTIVITY_SCORE = 100 when the curve fit is constant and showing full inhibition at all tested concentrations.
The individual dose data point columns ('Activity_at_xxuM') reported here represent the median of valid (unmasked) replicate observations at each concentration. These values are the inputs to a curve fitting algorithm.
All other data columns represent values which are derived during the curve fitting algorithm; this may sometimes include automatic further masking of some replicate data points.
Occasionally this results in perceived inconsistencies: for example, between the derived 'Maximal_Activity' and the apparent most active data point.
* Activity Concentration. ** Test Concentration.
Data Table (Concise)