Blog

Tagged: tutorial

46 posts found

Cell Line Pathway Analysis: Methods and Comparisons
Research Guide

Cell Line Pathway Analysis: Methods and Comparisons

Choose valid RNA-seq designs for pathway comparisons across cell lines, including additive adjustment, stratified effects, and treatment-by-cell-line interactions.

Abdullah Shahid ·
How Are Biological Pathways Connected?
Tutorial

How Are Biological Pathways Connected?

Learn how shared genes, leading-edge drivers, transcriptional regulation, and co-expression connect pathways and how to build an interpretable pathway network.

Abdullah Shahid ·
How to Build a Biological Pathway Diagram
Research Guide

How to Build a Biological Pathway Diagram

Build a scientifically honest pathway diagram by defining scope, typing nodes and edges, mapping identifiers, overlaying data, and exporting a reproducible graph.

Abdullah Shahid ·
How to Do Pathway Analysis with RNA-Seq
Tutorial

How to Do Pathway Analysis with RNA-Seq

A defensible RNA-seq pathway workflow: design contrasts, define the tested gene universe, rank genes, choose databases, control FDR, and audit driver genes.

Abdullah Shahid ·
How to Interpret Pathway Analysis Results
Tutorial

How to Interpret Pathway Analysis Results

Learn how to read pathway scores, FDR, direction, leading-edge genes, redundancy, topology evidence, and missing results without overstating the biology.

Abdullah Shahid ·
How to Compare Pathways Across Datasets
Tutorial

How to Compare Pathways Across Datasets

Compare pathway results across contrasts, studies, platforms, and species without losing direction, provenance, uncertainty, or missing values.

Abdullah Shahid ·
Pathway Enrichment vs Pathway Activity
Tutorial

Pathway Enrichment vs Pathway Activity

Pathway enrichment tests gene-set membership or rank shift; pathway activity models signed target responses. Learn why the scores differ and how to interpret each.

Abdullah Shahid ·
Pathway Visualization in Python
Tutorial

Pathway Visualization in Python

Build pathway lollipop plots, evidence matrices, ranked-gene barcodes, overlap networks, and regulator footprints in Python without hiding direction, FDR, or missing data.

Abdullah Shahid ·
What Is a Biological Pathway?
Tutorial

What Is a Biological Pathway?

A clear, technical guide to biological pathways, gene sets, pathway diagrams, signed graphs, networks, and how NotchBio keeps each evidence layer distinct.

Abdullah Shahid ·
What Is Pathway Analysis?
Tutorial

What Is Pathway Analysis?

Pathway analysis explained: choose ORA, ranked enrichment, topology analysis, or activity inference from the input and biological question.

Abdullah Shahid ·
Troubleshooting

RNA-Seq Read Length: Why Trimming Removes All Your Reads

Why RNA-seq trimming can discard every read, how read length and paired-end mismatches produce empty FASTQ files, and what to check before you run a pipeline.

Abdullah Shahid ·
Bioinformatics

How to Read a FastQC Report: Warnings, Failures, and Fixes

A senior bioinformatician walks through the FastQC sections that real beginners miss, with screenshots and decisions to make at each step.

Abdullah Shahid ·
Tutorial

STAR vs Salmon vs HISAT2: A Hands-On Benchmark

A hands-on RNA-seq aligner benchmark: working STAR, Salmon, and HISAT2 commands, real runtime and memory numbers, and how much the DEG list actually changes.

Abdullah Shahid ·
Tutorial

Salmon From FASTQ to Counts: A Complete Tutorial

A complete Salmon tutorial with decoy-aware indexing, quantification flags explained, tximport into R, DESeq2 integration, and QC checks at every step.

Abdullah Shahid ·
Tutorial

PyDESeq2 vs DESeq2 in R: Validation and Scanpy Workflow

Does PyDESeq2 really match R DESeq2? A tutorial on validating results against R, running PCA with scanpy and AnnData, and exporting DEGs for enrichment.

Abdullah Shahid ·
Tutorial

Publication-Ready RNA-Seq Plots in R with ggplot2

Reviewer-ready RNA-seq plots in R: volcano with gene labels, z-score heatmap with annotation bars, PCA with variance explained, and journal export settings.

Abdullah Shahid ·
Tutorial

ORA vs GSEA in R: clusterProfiler Pathway Analysis Tutorial

ORA and GSEA answer different questions. A working clusterProfiler tutorial with FDR correction, proper backgrounds, and side-by-side result interpretation.

Abdullah Shahid ·
Bioinformatics

GTF vs GFF3 Files: Format Differences and RNA-Seq Fixes

GTF and GFF files from the same database often disagree, prokaryotic files lack exon features, AGAT fixes some and breaks others. A practical field guide.

Abdullah Shahid ·
Tutorial

Nextflow RNA-Seq Tutorial: Build Your First Pipeline

A minimal Nextflow DSL2 RNA-seq pipeline in under 80 lines: three processes, channel wiring, Docker config, and how to read the execution report and DAG output.

Abdullah Shahid ·
Tutorial

Reducing GO Term Redundancy: simplify, rrvgo, and What Works

After enrichment you get hundreds of overlapping GO terms. A tutorial on clusterProfiler simplify, rrvgo, REVIGO, and a custom uniqueness-score fallback.

Abdullah Shahid ·
Tutorial

Pathway Enrichment Analysis: GSEA and ORA in R and Python

Pathway enrichment end to end: GSEA and ORA in R with clusterProfiler and fgsea, plus the Python equivalent with gseapy, across MSigDB, KEGG, and GO sets.

Abdullah Shahid ·
Tutorial

fastp vs Trimmomatic vs BBDuk: A Benchmark on RNA-Seq Reads

A side-by-side benchmark of fastp, Trimmomatic, and BBDuk on paired-end RNA-seq data: speed, post-trim quality, mapping rate, and downstream DEG impact.

Abdullah Shahid ·
Tutorial

DESeq2 Tutorial in R: Count Matrix to Volcano Plot

A complete DESeq2 tutorial in R: loading counts, building the design formula, running DE, applying lfcShrink, generating a volcano plot, and exporting results.

Abdullah Shahid ·
Tutorial

DESeq2 Contrasts: Multiple Conditions and Multi-Factor Designs

Three conditions, paired designs, two-factor experiments, and time courses: how to build the design formula, specify contrasts, and avoid common mistakes.

Abdullah Shahid ·
Tutorial

RNA-Seq Plots: Volcano, MA, and Heatmap in R and Python

Publication-ready RNA-seq plots in R and Python: volcano with ggplot2/ggrepel, MA plots, and DEG heatmaps with pheatmap and seaborn, plus 300 dpi export.

Abdullah Shahid ·
Tutorial

Bulk RNA-Seq Deconvolution: CIBERSORTx and MuSiC Tutorial

Estimate cell type proportions from bulk RNA-seq using CIBERSORTx and MuSiC. Reference selection, batch correction, validation, and result interpretation.

Abdullah Shahid ·
Tutorial

RNA-Seq Batch Correction: ComBat-Seq vs RUVSeq vs sva

How to choose a batch-effect correction tool: ComBat-Seq, RUVSeq, and sva compared, including unknown batch sources and reporting it in your methods.

Abdullah Shahid ·
Tutorial

Salmon to Differential Expression in Python with PyDESeq2

A pipeline-focused PyDESeq2 tutorial: load Salmon quant.sf into a count matrix, fit a DeseqDataSet, run Wald tests, apply apeGLM shrinkage, export DEGs. No R.

Abdullah Shahid ·
Tutorial

How to Run DESeq2 in R from Salmon quant.sf Files

DESeq2 in R from Salmon counts: import quant.sf with tximeta, build a DESeqDataSet, run the Wald test, apply apeglm shrinkage, and export a ranked DEG table.

Abdullah Shahid ·
Tutorial

How to Build a DESeq2 Count Matrix in Python

Python tutorial: parse featureCounts output, aggregate Salmon quant.sf, build a tx2gene map, and save a DESeq2-ready integer count matrix with pandas.

Abdullah Shahid ·
Tutorial

STAR RNA-Seq Alignment Tutorial: FASTQ to Gene Counts

Complete STAR tutorial: download genome and GTF, build an index with the right sjdbOverhang, run paired-end alignment, and load GeneCounts into R for DESeq2.

Abdullah Shahid ·
Tutorial

How to Build a Decoy-Aware Salmon Index for RNA-Seq

Step-by-step Salmon tutorial: download GENCODE references, build a decoy-aware index, run salmon quant with gcBias and seqBias, and verify mapping rates.

Abdullah Shahid ·
Tutorial

FASTQ Quality Control: FastQC, fastp, and MultiQC Workflow

Bulk RNA-seq QC end to end: run FastQC on raw reads, trim adapters with fastp, rerun QC, and aggregate everything into one MultiQC report, with parallel runs.

Abdullah Shahid ·
Tutorial

How to Download RNA-Seq FASTQ Data from GEO and SRA

Download bulk RNA-seq FASTQ files from GEO and SRA: prefetch, fasterq-dump, pysradb metadata, batch downloads, and fixes for the most common errors.

Abdullah Shahid ·
Tutorial

Volcano and MA Plots in R: DESeq2 and ggplot2 Tutorial

Publication-quality volcano and MA plots from DESeq2 results in R: ggplot2 from scratch, ggrepel gene labels, EnhancedVolcano, and how to read them.

Abdullah Shahid ·
Tutorial

RNA-Seq PCA and Sample Clustering in Python: QC Tutorial

Python tutorial: normalize RNA-seq counts, run PCA with scikit-learn, build a sample distance heatmap, and spot outliers before differential expression.

Abdullah Shahid ·
Tutorial

PyDESeq2 Tutorial: Differential Expression Analysis in Python

The complete PyDESeq2 reference in Python: DeseqDataSet, DeseqStats, apeglm shrinkage, multi-factor designs, multiple contrasts, and pandas result filtering.

Abdullah Shahid ·
Tutorial

DESeq2 Tutorial in R: From Count Matrix to Results

Step-by-step DESeq2 in R: build a DESeqDataSet, understand size factors and dispersion, run DESeq(), interpret the results columns, then shrink and filter DEGs.

Abdullah Shahid ·
Tutorial

Set Up an RNA-Seq Conda Environment on Ubuntu or macOS

Install Miniforge, conda, bioconda, R 4.4, and DESeq2 for bulk RNA-seq: reproducible environments, version pinning, and fixes for common install errors.

Abdullah Shahid ·
Tutorial

Salmon quant.sf Explained: Mapping Rates and DESeq2 Import

Understand Salmon quant.sf columns, mapping rates, effective length, NumReads, TPM, and the correct handoff to tximport, tximeta, and DESeq2.

Abdullah Shahid ·
Tutorial

tximport vs tximeta: Import Salmon quant.sf into DESeq2

Import Salmon quant.sf into R with tximeta and tximport: build a tx2gene table, fix ID-mismatch errors, and set up a DESeqDataSet for multi-factor designs.

Abdullah Shahid ·
Research Guide

STAR vs HISAT2 vs Salmon: Which Aligner Should You Use?

STAR aligns to the genome, HISAT2 uses less memory, Salmon skips alignment. What each approach means for your RNA-seq results and when each is the right call.

Abdullah Shahid ·
Research Guide

RNA-Seq Sample Preparation: RNA Extraction to FASTQ Files

RNA-seq sample preparation from RNA extraction and quality checks through library preparation, Illumina sequencing, base calling, and FASTQ files.

Abdullah Shahid ·
Tutorial

fastp vs Trimmomatic: RNA-Seq Adapter Trimming Tutorial

When adapter trimming helps, when it hurts, and how to run Trimmomatic and fastp on RNA-seq data with the parameter choices that actually matter.

Abdullah Shahid ·
Tutorial

How to Run FastQC and MultiQC on Multiple FASTQ Files

A hands-on guide to automating RNA-seq QC across dozens of samples using FastQC and MultiQC, with bash and Python scripts for parsing and flagging failures.

Abdullah Shahid ·
Research Guide

Bulk RNA-Seq Pipeline: FASTQ to Gene Counts Step by Step

Every computational step in bulk RNA-seq, explained: from FASTQ quality control through trimming, alignment, and quantification to your final count matrix.

Abdullah Shahid ·