StatLIA® measures relative potency and parallelism even for bioassays that yield difficult, illbehaved data.
StatLIA® Parallelism measures the biological similarity between two molecules quantitatively, where parallelism and nonparallelism can be directly compared. StatLIA® Parallelism using methodology provides results that are:
Click to enlarge 
 Consistent
Determine potency even for assays with high variation using StatLIA’s correct weighting

Click to enlarge 
 Accurate
Improve the accuracy of full curve parallelism analysis with StatLIA’s TrueFit™ 5PL

Click to enlarge 
 Reliable
Measure parallelism and nonparallelism directly, accurately, every time using method

Presentations and Posters
U.S. Pharmacopeia Bioassay Workshop, August 2008
Download Brendan CTO Presentation: "Nonlinear Systems: A Comparison of Approaches to Similarity Testing."
Link to all Presentations at USP Bioassay Workshop.
IBC Biological Assay Development & Validation Conference, May 2008
Download MERCK Presentation:
(MERCK Uses STATLIA Parallelism Metric to Set Acceptance Criteria)
Download Presentation: "Comparison of Methods Used to Measure Parallelism"
Download Poster: "Comparison of Methods Used to Measure Parallelism"
Data: (Request Data Used In Parallelism Comparison Study)
Reference
Measuring Parallelism, Linearity and Relative Potency in Bioassay and Immunoassay Data, Gottschalk PG, Dunn JR, Journal of Biopharmaceutical Statistics, 2005; 3:437463. (Free Reprint Available)


Key Parallelism Metrics
 Probability: Probability the two curves are parallel based on the ChiSquare statistic
 Statistic: Direct measure of the amount of nonparallelism between two curves
 Relative Potency: Relative potency between the two curves
 Low Confidence Limit: Lower 95% confidence limit for the relative potency
 High Confidence Limit: Upper 95% confidence limit for the relative potency
 Confidence Limit Ratio: Ratio of the logs of the upper and lower confidence limits
 IC25, IC50, IC75: Percent concentration of the maximum response calculated from the unknown dilution curve
 Dil25, Dil50, Dil75: Equivalent dilution factor of the inhibitory concentration, e.g. (Dil*Conc)/IC50
 Fit Probability: Measurement of how well the computed curve fit the observed data points
 Limits of Quantitation and Detection: Limits of Quantitation and Detection based on the observed data points
 Dilution CV's: Coefficient of variation of all reportable concentrations in a dilution series
 Download Parallelism Poster PDF File
 Download Parallelism PDF File


Full Logistic Curve Parallelism Method
 Use a powerful weighted 5 parameter or 4 parameter logistic model to fit the curves
 Measure the reliability of the standard curve
 Measure the reliability of the unknown dilution curve
 Measure the parallelism between the two curves using the Statistic and Probability
 Download Parallelism Fact Sheet PDF file

