Assay Quality Quick Calculator
Calculate Z′, S/B, S/N, CV, and 95% confidence intervals from control summaries.
Enter sample SD (n-1 denominator). n is the number of independent replicates used to produce each control mean and SD.
Assay QC results
Enter valid mean, SD, and n values.
This tool reports metrics and does not automatically pass or fail an assay. Review control suitability, plate drift, edge effects, and protocol-specific criteria.
Sources: Zhang, Chung & Oldenburg (1999), DOI 10.1177/108705719900400206; NIH/NCATS Assay Guidance Manual; NIST/SEMATECH e-Handbook §1.3.5.2.
Tool Guide
Definition
Assay Quality Quick Calculator — Enter the mean, sample standard deviation, and replicate count for positive and negative controls to calculate Z′, signal-to-background, signal-to-noise, signal window, CV, and 95% confidence intervals for the means.
Purpose
(1) Quickly summarize control separation and variability in HTS or plate assays (2) Compare Z′ and CV across experimental runs (3) Cross-check QC metrics for reports (4) Review summary values before raw-plate analysis
How to Use
① Enter mean, sample SD (n−1), and replicate n for positive and negative controls. ② Results update instantly. ③ Copy the metrics into a report draft. At least two replicates per control are required. No automatic pass/fail decision is made. Use the Bio-Sandbox Bioassay Plate QC app for raw 96/384-well CSV, spatial review, and hit tables.
Examples
Example) Positive control mean=100, SD=2, n=4; negative control mean=10, SD=1, n=4 → Z′=0.900, S/B=10.0, S/N=30.0, signal window=81 → Positive-control 95% CI=96.818–103.182 These are calculated metrics; assay suitability still requires protocol-specific and whole-plate review.