Labreador — Bioassay Analysis Platform Blog

    Methodology notes, step-by-step guides, and release notes for scientific bioassay analysis.

    Method Validation

    Spike Recovery and Dilution Linearity in ELISA: How to Prove Your Matrix Is Not Lying

    Practical protocols and acceptance criteria for ELISA spike recovery, dilution linearity and parallelism — how to detect matrix effects, the hook effect and the correct minimum required dilution.

    September 3, 20266 min read
    Kinetics

    How to Calculate Km and Vmax: A Practical Enzyme Kinetics Guide

    Step-by-step guide to Michaelis-Menten kinetics: measuring initial rates, fitting Km and Vmax, why Lineweaver-Burk plots mislead, and how to report results correctly.

    August 29, 20266 min read
    ELISA

    4PL vs 5PL for ELISA Standard Curves: Why Log-Linear Regression Fails

    ELISA standard curves are sigmoidal, not straight. Learn why four-parameter logistic (4PL) and five-parameter logistic (5PL) fitting outperforms linear or log-linear regression, and when to use each model.

    August 25, 20264 min read
    Method Validation

    How to Calculate LOD and LOQ: Formulas, Methods and Common Mistakes

    Three accepted ways to calculate the limit of detection (LOD) and limit of quantitation (LOQ) — blank SD, calibration-curve residuals, and the S/N approach — with formulas, worked numbers and reporting rules.

    August 23, 20265 min read
    Ecotoxicology

    BCF, BAF and BSAF: How to Calculate Bioaccumulation Factors Correctly

    A practical guide to bioconcentration (BCF), bioaccumulation (BAF) and biota-sediment accumulation (BSAF) factors — formulas, units, dry vs wet weight, non-detects, and how to interpret the thresholds.

    August 17, 20265 min read
    ELISA

    ELISA Data Analysis: A Step-by-Step Guide (2026)

    How to analyze ELISA data end to end: blank subtraction, 4PL/5PL standard curve fitting, sample interpolation, LLOQ/ULOQ limits, %CV and recovery checks.

    August 2, 20264 min read
    Data & Privacy

    Local-First Science: Why Your Assay Data Should Never Leave the Browser

    In 2026, cloud-hosted lab tools are quietly training on your raw data. Here is why local-first, zero-data-storage scientific software is becoming the new default — and how Labreador implements it.

    July 27, 20264 min read
    ELISA

    Beyond R²: What to Actually Check for ELISA Method Quality

    A practical checklist of the metrics that decide whether an ELISA run is trustworthy — dynamic range, S/B, EC50 placement, CI width, recovery — and how Labreador's Method Health Panel surfaces them automatically.

    July 22, 20265 min read
    Release Notes

    Labreador v1.5 — Parallel Line Analysis, Combined Assays, and Smarter Diagnostics

    What is new in Labreador v1.5: a full Parallel Line Analysis module with relative potency, multi-run combination, Fieller CI, weighted regression, and quality-of-life polish across the app.

    July 13, 20263 min read
    Bioassay QC

    Parallel Line Analysis: The One Test That Separates Biosimilars From Bench Curiosities

    Why pharmacopoeias require Parallel Line Analysis for every batch of a biological product, how relative potency is actually computed, and the failure modes that quietly invalidate it.

    July 1, 20266 min read
    Assay QC

    Z'-Factor: The One Number That Tells You If Your Assay Is Worth Running

    How the Z'-factor separates publishable assays from noise, why 0.5 is the magic threshold, and how to calculate it correctly for ELISA, dose-response, and HTS screens.

    June 30, 20265 min read
    Dose-Response

    IC50 vs EC50: What They Mean, How to Calculate Them, and When Each Applies

    Clear, practical guide to IC50 and EC50: definitions, when to use which, how they're calculated from a dose-response curve, and common pitfalls in fitting and reporting.

    June 18, 20266 min read
    ELISA

    R² Is Not Enough: A 3-Tier Quality Gate for ELISA Curves

    Why a single R² value misleads on heteroscedastic ELISA curves, and how a 3-tier acceptance gate (≥0.98 / 0.95–0.98 / <0.95) protects sample interpolation.

    May 26, 20265 min read
    Ecotoxicology

    Understanding Pollution Indices: CF, PLI and MPI Explained

    A practical guide to Contamination Factor, Pollution Load Index and Metal Pollution Index — what they measure, how they are calculated, and how to interpret them in environmental studies.

    May 6, 20264 min read
    Announcements

    Welcome to the Labreador Blog

    An introduction to the Labreador blog — practical guides on bioassay analysis, methodology notes, and tutorials for ELISA, dose-response, kinetic, and ecotoxicology workflows.

    April 21, 20261 min read