STATISTICAL SOFTWARE
GraphPad Prism Data Analysis Service
Bench Data Analyzed to the Right Unit
Our GraphPad Prism data analysis service carries out group comparisons, curve fitting and survival analysis for bench and preclinical studies in Prism, working from your project files, with the experimental unit defined first and the Prism project and exact analysis settings provided where agreed.
No Commitment Required
Strictly Confidential
In-House PhD-Level Statisticians
Fixed Project Fee
Same-Day Response
What Is GraphPad Prism Used For in Research?
GraphPad Prism is a commercial package for scientific graphing and statistics, widely used in laboratory, preclinical and biomedical research. Researchers choose it for its group comparisons, nonlinear regression for dose-response and other curves, survival analysis and publication-style graphs, held together in a project file in which graphs and results follow the data tables. That convenience also makes it easy to analyze data in a way the design does not support. OnlineSPSS, a specialist statistical consultancy for academic, clinical and professional research, provides a GraphPad Prism data analysis service in which an in-house PhD-level statistician carries out the agreed analysis in Prism, working from your project files and recording every setting.
WHEN TO ENGAGE
Four Points at Which Laboratory Teams Bring Us a Prism Project
GraphPad analysis consulting is requested at different stages of an experiment series, from a finished set of results to a project file inherited from a colleague.
Experiments Ready to Analyze Several experiments are complete and the comparisons were planned, and you need the right test chosen for the design, with effect sizes and confidence intervals reported beyond a significance star.
Replicates You Cannot Tell Apart Wells, animals and independent experiments sit in one data table, and the experimental unit has to be defined before any test is trusted or any n is reported.
Curve Fit to Justify Prism curve fitting of a dose-response or kinetic model returns an EC50 or IC50, and a supervisor or reviewer asks about the model, the constraints and the residuals behind it.
Project to Rebuild or Check A Prism project left by a previous researcher or lab member needs its analyses checked and its settings documented, without rebuilding everything in another program.
ANALYSES IN PRISM
Analyses Carried Out in Prism for Your Experimental Design
Each analysis is matched to the design and the experimental unit, and its card links to the method page where the choice of test is explained.
Independent Samples t-Test
Two independent groups of animals or cultures are compared with a test that allows unequal variances, and the mean difference is reported with its 95% confidence interval and an effect size.
Paired Samples t-Test
Before-and-after values on the same animals or matched samples are analyzed as pairs, because treating them as two independent groups discards the pairing and widens the interval.
One-Way ANOVA
Several treatment groups are compared in one model, followed by multiple comparisons such as Dunnett against a control or Tukey among all pairs, reported with adjusted intervals.
Repeated Measures ANOVA
Time courses on the same animals or cultures keep their repeated structure, with a sphericity correction, or a mixed-effects model when some values are missing.
Simple Linear Regression
Standard curves and calibration lines are fitted with slope and intercept reported with confidence intervals, and unknowns are interpolated with their uncertainty.
Survival Analysis
Animal survival is shown as Kaplan-Meier curves with censoring recorded, compared with the log-rank test and summarized as a hazard ratio with its confidence interval.
COMMON PRISM ISSUES
Where Bench Analyses Go Wrong Before the Test
Most problems in Prism projects come from how replicates were entered and which model was chosen, not from a button, so each check below is made before a result is reported.
Replicate Subcolumns Are Not n Prism treats values in replicate subcolumns as independent observations unless matching is set. Wells from one culture entered there inflate n, so one value per animal or independent experiment is entered, or values are matched by experiment in the analysis.
Equation Matched to the X Values Prism's log(agonist) equations expect X as log concentration, and a zero-dose control cannot be logged, so it drops out of the fit unless it is entered differently. The equation, its constraints and the X scale are chosen together, and the EC50 is reported with its confidence interval.
Residuals and Weighting Residuals are examined for pattern and for spread that grows with the response, and weighting or a transformation is used when it does, because the interval around an estimate is otherwise misstated.
Normalized and Percent Data Values expressed as percent of control or of maximum remove the variability of the reference group, so the normalization is decided before testing and stated, and a test on normalized data is read with that in mind.
Comparisons Matched to the Design Many separate t-tests on one experiment inflate the false-positive rate. One model with an adjustment that fits the planned comparisons is used, and the family of comparisons is stated.
Graphs That Hide the Data A bar of the mean with the standard error conceals the distribution and the n. Individual points are shown with an interval or the standard deviation, and the legend names the error type.
DELIVERABLES
What You Receive From a Prism Analysis
The files follow a documented Prism workflow, agreed in the scope and provided where applicable, so that anyone in your laboratory can open the project and reproduce the analysis.
Prism Project File The project with data tables, analyses and graphs linked, so that a corrected value updates every result that depends on it.
Exact Analysis Settings A record of the settings of each analysis: the test, the corrections, the constraints and weighting of each fit and the multiple-comparison method.
Publication-Ready Graphs Graphs that show individual points with the mean and an interval, exported in the formats the target journal asks for, with the error type named.
Results Tables Tables with estimates, 95% confidence intervals, exact P values where reported and the n behind each, in Word or Excel as agreed.
Statistical Interpretation Each result is explained within what the design supports, with its limitations stated plainly so that you can address them in the discussion.
Replication Structure Note A short note that defines the experimental unit and the n for each comparison, so that reviewers can see how the replicates were handled.
OTHER PLATFORMS
When Another Platform May Be More Appropriate
Prism suits many laboratory projects, but the software follows the design, and some analyses fit another platform better.
ILLUSTRATIVE EXAMPLE
How a Prism Analysis May Look in Practice
An illustration of how a two-factor cell culture experiment moves from replicate wells to a test that matches the design.
ILLUSTRATIVE EXAMPLE · BONE CELL CULTURE RESEARCH · UNITED STATES
A university orthopedic research laboratory compared mineral deposition by bone-forming cells from wild-type and knockout mice, with and without an osteogenic treatment, in three independent experiments, each plated in triplicate wells.
The results sat in a Prism grouped table with the wells of all three experiments entered as replicates, so the two-way ANOVA treated nine values per condition as independent and returned a very small P value for the interaction. The experimental unit was redefined as the independent experiment: the wells were averaged within each experiment, and because readings from one experiment ran higher or lower together, values were matched by experiment so that day-to-day shifts were separated from the effects of genotype and treatment. The comparisons of interest, treatment within each genotype, were stated in advance and adjusted as one family. The graph was rebuilt to show each experiment’s value, so that a reader sees three points per condition and not a bar of the mean.
Outcome: The laboratory received the Prism project with linked data tables, the exact analysis settings, graphs showing each independent experiment, the interaction estimate with its 95% confidence interval and a note defining the experimental unit.
This example does not describe a real client or project. We never share details of actual client work, in line with the confidentiality we promise every researcher. This illustrative example is included to show the type, scope, and standard of work involved in this kind of analysis.
RESEARCH DISCIPLINES
Research Fields Where Prism Is Common
Prism biostatistics is common in life sciences and biomedical research, where the same questions about replicates, curves and group comparisons arise in every field that works with experimental data.
HOW WE ASSESS YOUR PROJECT
We Review Your Actual Research
Your assessment is based on a review of your actual research materials and analytical requirements, not a generic project category.
You Submit Your Project Details
Share whatever is available at the current stage, such as the research aim, protocol or proposal, dataset, variable list, manuscript or statistical requirements.
We Review Your Research and Define the Scope
Your statistically trained Research Coordinator reviews the materials to understand the study design, research questions, data structure, analytical requirements and expected deliverables. If clarification is needed, additional documents or information can be requested before the assessment is finalized.
Your Analysis Is Completed and Delivered
Once the scope and fixed project fee are agreed, the in-house statistician completes the work and the Research Coordinator remains the communication point through delivery, with the analysis, deliverables and timeline as agreed.
RESEARCHER VOICE
What Researchers Say
Feedback from a biomedical research scientist on technical and biological replicates, and on a workflow rebuilt from the files already in hand.
“We already had most of the project in GraphPad Prism, but our main issue was technical replicates being mistaken for independent biological replicates. The team worked from the files we already had, cleaned up the workflow, and returned the analysis in a form we could reproduce. I especially appreciated not having to rebuild everything in another program.”
Statistical Support Within Your Research OnlineSPSS provides the agreed methodological, analytical and statistical reporting support, including the Prism files described in the scope. The researcher or research team retains the scientific question, substantive interpretation, conclusions and overall responsibility for the research.
FREQUENTLY ASKED QUESTIONS
Questions About Prism Analysis for Research
Short answers to what researchers ask before sharing a Prism project, from the analyses we carry out and existing projects to replicate fitting, EC50 reporting and confidentiality.
Which analyses do you carry out in Prism?
GraphPad Prism statistical analysis at OnlineSPSS covers the comparisons and models laboratory studies most often use: t-tests, one-way and repeated measures ANOVA, regression and curve fitting, and survival analysis. The choice follows your design and the experimental unit, and it is confirmed during the assessment.
Can you work from my existing Prism project, or only from exported numbers?
We work from the project file itself, with its data tables, analyses and graphs, so that you do not have to rebuild anything in another program. If the analyses were already run, Independent Statistical Review checks each analysis sheet against the design, from the table type and replicate layout to the test chosen.
Should Prism fit my curve to every replicate or to the means?
To independent values only. Prism fits every replicate Y value as its own point unless told otherwise, which is right when the replicates are independent. Wells from one plate are not, so within one experiment the fit uses their means, set on the Weights tab, and the precision of the estimate rests on repeated independent experiments, not on the number of wells.
Is the EC50 enough to report for a dose-response experiment?
Not on its own. A curve estimate is reported with its confidence interval, the model and constraints used, and a check of the residuals, so that a reader can judge how well the curve describes the data and how precisely the potency is known.
How do you protect my research data and confidentiality?
Your Prism projects, raw data and figures are handled confidentially, and project information is not published. An NDA is available where required and can be arranged before sensitive materials are shared. Read more about confidentiality and data security.
What happens when I request an assessment, and how long does it take?
You share your research question, design and relevant materials, such as the Prism project and any protocol, and a statistically trained Research Coordinator reviews the request and responds the same day. The analysis, deliverables, timeline and one fixed project fee are then confirmed before any work begins, so the timeline follows from the agreed scope.
Still have a question? Find more answers in our full FAQ.
NEXT STEP
Discuss Your
Prism Analysis With Us
Share your research question, your Prism project or data, and the comparisons you have in mind. We check how the replicates were entered and confirm the analysis before any work begins.
No Commitment Required
Strictly Confidential
Fixed Project Fee
In-House PhD-Level Statisticians
Same-Day Response
Serving Researchers Since 2014