qPCR: Biological vs Technical Replicates (n-value)
What counts as n in qPCR? Average technical replicates within each biological replicate, then run statistics on biological replicates only — with Livak 2^-ddCt and Pfaffl worked examples.
SciKeep Blog — notes on lab analysis
Method notes on the analyses these tools perform, and the mistakes they are built to catch.
MSA Explained: Needleman-Wunsch and Progressive Guide Trees
How progressive multiple sequence alignment works: pairwise distance matrices, UPGMA guide trees, affine gap penalties and consensus conservation symbols.
Watershed vs Thresholding for Touching Cells
Why Otsu thresholding merges touching cells, and how Chamfer distance transforms plus watershed de-clumping resolve individual nuclei in confluent micrographs.
How to Read Kaplan-Meier Survival Curves
Product-limit survival estimation, right-censoring and the Mantel-Cox log-rank test, explained for preclinical and clinical survival data.
21 CFR Part 11: SHA-256 Audit Trails in the Lab
How tamper-evident SHA-256 hash chains, role-based digital signatures and encrypted vault exports support FDA 21 CFR Part 11 compliance in an electronic lab notebook.
CRISPR gRNA Scoring: On-Target vs Off-Target
GC content, seed-region composition, poly-T termination and PAM spacing: how CRISPR guide RNAs are scored, ranked and screened for off-target risk.
qPCR Quantification: the Livak 2^-ddCt Method
The mathematical derivation of Livak and Schmittgen ΔΔCt, housekeeping-gene normalisation, Pfaffl efficiency correction and error propagation.
Gibson Assembly vs Golden Gate: Overlap Design
Homology arm design, SantaLucia nearest-neighbour melting temperatures and molar ratio optimisation for isothermal Gibson assembly and Golden Gate cloning.
IC50 Fitting: Why You Need 4-Parameter Logistic
Linear interpolation of dose-response points distorts potency estimates. How non-linear least-squares 4PL regression recovers true IC50, Hill slope and R².
Protein pI: Why It Matters and How It's Calculated
How the Henderson-Hasselbalch bisection algorithm computes pI, why different tools disagree, and why a folded protein can sit half a pH unit from the calculated value.
Statistical Power: How to Size Your Sample
Calculate sample size per group with Cohen effect sizes and alpha thresholds, and generate grant-ready power analysis boilerplate.
qPCR Master Mix Batching and Dead-Volume Overage
Common master mixes, +10% dead-volume overage and bench checklists that stop pipetting runouts across 96- and 384-well plates.
SuperPlots: Fixing N=1 Pseudoreplication
Treating 500 cells from one dish as N=500 inflates false positives. How SuperPlots combine single-cell spread with independent experiment means.
Drug Synergy: Bliss Independence Explained
How the Bliss independence model scores a drug-combination dose matrix, and what public screens such as NCI ALMANAC can and cannot tell you.