LogoLogo
Illumina KnowledgeIllumina SupportSign In
Partek
  • Home
Partek
  • Overview
  • Partek Flow
    • Frequently Asked Questions
      • General
      • Visualization
      • Statistics
      • Biological Interpretation
      • How to cite Partek software
    • Quick Start Guide
    • Installation Guide
      • Minimum System Requirements
      • Single Cell Toolkit System Requirements
      • Single Node Installation
      • Single Node Amazon Web Services Deployment
      • Multi-Node Cluster Installation
      • Creating Restricted User Folders within the Partek Flow server
      • Updating Partek Flow
      • Uninstalling Partek Flow
      • Dependencies
      • Docker and Docker-compose
      • Java KeyStore and Certificates
      • Kubernetes
    • Live Training Event Recordings
      • Bulk RNA-Seq Analysis Training
      • Basic scRNA-Seq Analysis & Visualization Training
      • Advanced scRNA-Seq Data Analysis Training
      • Bulk RNA-Seq and ATAC-Seq Integration Training
      • Spatial Transcriptomics Data Analysis Training
      • scRNA and scATAC Data Integration Training
    • Tutorials
      • Creating and Analyzing a Project
        • Creating a New Project
        • The Metadata Tab
        • The Analyses Tab
        • The Log Tab
        • The Project Settings Tab
        • The Attachments Tab
        • Project Management
        • Importing a GEO / ENA project
      • Bulk RNA-Seq
        • Importing the tutorial data set
        • Adding sample attributes
        • Running pre-alignment QA/QC
        • Trimming bases and filtering reads
        • Aligning to a reference genome
        • Running post-alignment QA/QC
        • Quantifying to an annotation model
        • Filtering features
        • Normalizing counts
        • Exploring the data set with PCA
        • Performing differential expression analysis with DESeq2
        • Viewing DESeq2 results and creating a gene list
        • Viewing a dot plot for a gene
        • Visualizing gene expression in Chromosome view
        • Generating a hierarchical clustering heatmap
        • Performing biological interpretation
        • Saving and running a pipeline
      • Analyzing Single Cell RNA-Seq Data
      • Analyzing CITE-Seq Data
        • Importing Feature Barcoding Data
        • Data Processing
        • Dimensionality Reduction and Clustering
        • Classifying Cells
        • Differentially Expressed Proteins and Genes
      • 10x Genomics Visium Spatial Data Analysis
        • Start with pre-processed Space Ranger output files
        • Start with 10x Genomics Visium fastq files
        • Spatial data analysis steps
        • View tissue images
      • 10x Genomics Xenium Data Analysis
        • Import 10x Genomics Xenium Analyzer output
        • Process Xenium data
        • Perform Exploratory analysis
        • Make comparisons using Compute biomarkers and Biological interpretation
      • Single Cell RNA-Seq Analysis (Multiple Samples)
        • Getting started with the tutorial data set
        • Classify cells from multiple samples using t-SNE
        • Compare expression between cell types with multiple samples
      • Analyzing Single Cell ATAC-Seq data
      • Analyzing Illumina Infinium Methylation array data
      • NanoString CosMx Tutorial
        • Importing CosMx data
        • QA/QC, data processing, and dimension reduction
        • Cell typing
        • Classify subpopulations & differential expression analysis
    • User Manual
      • Interface
      • Importing Data
        • SFTP File Transfer Instructions
        • Import single cell data
        • Importing 10x Genomics Matrix Files
        • Importing and Demultiplexing Illumina BCL Files
        • Partek Flow Uploader for Ion Torrent
        • Importing 10x Genomics .bcl Files
        • Import a GEO / ENA project
      • Task Menu
        • Task actions
        • Data summary report
        • QA/QC
          • Pre-alignment QA/QC
          • ERCC Assessment
          • Post-alignment QA/QC
          • Coverage Report
          • Validate Variants
          • Feature distribution
          • Single-cell QA/QC
          • Cell barcode QA/QC
        • Pre-alignment tools
          • Trim bases
          • Trim adapters
          • Filter reads
          • Trim tags
        • Post-alignment tools
          • Filter alignments
          • Convert alignments to unaligned reads
          • Combine alignments
          • Deduplicate UMIs
          • Downscale alignments
        • Annotation/Metadata
          • Annotate cells
          • Annotation report
          • Publish cell attributes to project
          • Attribute report
          • Annotate Visium image
        • Pre-analysis tools
          • Generate group cell counts
          • Pool cells
          • Split matrix
          • Hashtag demultiplexing
          • Merge matrices
          • Descriptive statistics
          • Spot clean
        • Aligners
        • Quantification
          • Quantify to annotation model (Partek E/M)
          • Quantify to transcriptome (Cufflinks)
          • Quantify to reference (Partek E/M)
          • Quantify regions
          • HTSeq
          • Count feature barcodes
          • Salmon
        • Filtering
          • Filter features
          • Filter groups (samples or cells)
          • Filter barcodes
          • Split by attribute
          • Downsample Cells
        • Normalization and scaling
          • Impute low expression
          • Impute missing values
          • Normalization
          • Normalize to baseline
          • Normalize to housekeeping genes
          • Scran deconvolution
          • SCTransform
          • TF-IDF normalization
        • Batch removal
          • General linear model
          • Harmony
          • Seurat3 integration
        • Differential Analysis
          • GSA
          • ANOVA/LIMMA-trend/LIMMA-voom
          • Kruskal-Wallis
          • Detect alt-splicing (ANOVA)
          • DESeq2(R) vs DESeq2
          • Hurdle model
          • Compute biomarkers
          • Transcript Expression Analysis - Cuffdiff
          • Troubleshooting
        • Survival Analysis with Cox regression and Kaplan-Meier analysis - Partek Flow
        • Exploratory Analysis
          • Graph-based Clustering
          • K-means Clustering
          • Compare Clusters
          • PCA
          • t-SNE
          • UMAP
          • Hierarchical Clustering
          • AUCell
          • Find multimodal neighbors
          • SVD
          • CellPhoneDB
        • Trajectory Analysis
          • Trajectory Analysis (Monocle 2)
          • Trajectory Analysis (Monocle 3)
        • Variant Callers
          • SAMtools
          • FreeBayes
          • LoFreq
        • Variant Analysis
          • Fusion Gene Detection
          • Annotate Variants
          • Annotate Variants (SnpEff)
          • Annotate Variants (VEP)
          • Filter Variants
          • Summarize Cohort Mutations
          • Combine Variants
        • Copy Number Analysis (CNVkit)
        • Peak Callers (MACS2)
        • Peak analysis
          • Annotate Peaks
          • Filter peaks
          • Promoter sum matrix
        • Motif Detection
        • Metagenomics
          • Kraken
          • Alpha & beta diversity
          • Choose taxonomic level
        • 10x Genomics
          • Cell Ranger - Gene Expression
          • Cell Ranger - ATAC
          • Space Ranger
          • STARsolo
        • V(D)J Analysis
        • Biological Interpretation
          • Gene Set Enrichment
          • GSEA
        • Correlation
          • Correlation analysis
          • Sample Correlation
          • Similarity matrix
        • Export
        • Classification
        • Feature linkage analysis
      • Data Viewer
      • Visualizations
        • Chromosome View
          • Launching the Chromosome View
          • Navigating Through the View
          • Selecting Data Tracks for Visualization
          • Visualizing the Results Using Data Tracks
          • Annotating the Results
          • Customizing the View
        • Dot Plot
        • Volcano Plot
        • List Generator (Venn Diagram)
        • Sankey Plot
        • Transcription Start Site (TSS) Plot
        • Sources of variation plot
        • Interaction Plots
        • Correlation Plot
        • Pie Chart
        • Histograms
        • Heatmaps
        • PCA, UMAP and tSNE scatter plots
        • Stacked Violin Plot
      • Pipelines
        • Making a Pipeline
        • Running a Pipeline
        • Downloading and Sharing a Pipeline
        • Previewing a Pipeline
        • Deleting a Pipeline
        • Importing a Pipeline
      • Large File Viewer
      • Settings
        • Personal
          • My Profile
          • My Preferences
          • Forgot Password
        • System
          • System Information
          • System Preferences
          • LDAP Configuration
        • Components
          • Filter Management
          • Library File Management
            • Library File Management Settings
            • Library File Management Page
            • Selecting an Assembly
            • Library Files
            • Update Library Index
            • Creating an Assembly on the Library File Management Page
            • Adding Library Files on the Library File Management Page
            • Adding a Reference Sequence
            • Adding a Cytoband
            • Adding Reference Aligner Indexes
            • Adding a Gene Set
            • Adding a Variant Annotation Database
            • Adding a SnpEff Variant Database
            • Adding a Variant Effect Predictor (VEP) Database
            • Adding an Annotation Model
            • Adding Aligner Indexes Based on an Annotation Model
            • Adding Library Files from Within a Project
            • Microarray Library Files
            • Adding Prep kit
            • Removing Library Files
          • Option Set Management
          • Task Management
          • Pipeline managment
          • Lists
        • Access
          • User Management
          • Group Management
          • Licensing
          • Directory Permissions
          • Access Control Log
          • Failed Logins
          • Orphaned files
        • Usage
          • System Queue
          • System Resources
          • Usage Report
      • Server Management
        • Backing Up the Database
        • System Administrator Guide (Linux)
        • Diagnosing Issues
        • Moving Data
        • Partek Flow Worker Allocator
      • Enterprise Features and Toolkits
        • REST API
          • REST API Command List
      • Microarray Toolkit
        • Importing Custom Microarrays
      • Glossary
    • Webinars
    • Blog Posts
      • How to select the best single cell quality control thresholds
      • Cellular Differentiation Using Trajectory Analysis & Single Cell RNA-Seq Data
      • Spatial transcriptomics—what’s the big deal and why you should do it
      • Detecting differential gene expression in single cell RNA-Seq analysis
      • Batch remover for single cell data
      • How to perform single cell RNA sequencing: exploratory analysis
      • Single Cell Multiomics Analysis: Strategies for Integration
      • Pathway Analysis: ANOVA vs. Enrichment Analysis
      • Studying Immunotherapy with Multiomics: Simultaneous Measurement of Gene and Protein
      • How to Integrate ChIP-Seq and RNA-Seq Data
      • Enjoy Responsibly!
      • To Boldly Go…
      • Get to Know Your Cell
      • Aliens Among Us: How I Analyzed Non-Model Organism Data in Partek Flow
    • White Papers
      • Understanding Reads in RNA-Seq Analysis
      • RNA-Seq Quantification
      • Gene-specific Analysis
      • Gene Set ANOVA
      • Partek Flow Security
      • Single Cell Scaling
      • UMI Deduplication in Partek Flow
      • Mapping error statistics
    • Release Notes
      • Release Notes Archive - Partek Flow 10
  • Partek Genomics Suite
    • Installation Guide
      • Minimum System Requirements
      • Computer Host ID Retrieval
      • Node Locked Installation
        • Windows Installation
        • Macintosh Installation
      • Floating/Locked Floating Installation
        • Linux Installation
          • FlexNet Installation on Linux
        • Installing FlexNet on Windows
        • License Server FAQ's
        • Client Computer Connection to License Server
      • Uninstalling Partek Genomics Suite
      • Updating to Version 7.0
      • License Types
      • Installation FAQs
    • User Manual
      • Lists
        • Importing a text file list
        • Adding annotations to a gene list
        • Tasks available for a gene list
        • Starting with a list of genomic regions
        • Starting with a list of SNPs
        • Importing a BED file
        • Additional options for lists
      • Annotation
      • Hierarchical Clustering Analysis
      • Gene Ontology ANOVA
        • Implementation Details
        • Configuring the GO ANOVA Dialog
        • Performing GO ANOVA
        • GO ANOVA Output
        • GO ANOVA Visualisations
        • Recommended Filters
      • Visualizations
        • Dot Plot
        • Profile Plot
        • XY Plot / Bar Chart
        • Volcano Plot
        • Scatter Plot and MA Plot
        • Sort Rows by Prototype
        • Manhattan Plot
        • Violin Plot
      • Visualizing NGS Data
      • Chromosome View
      • Methylation Workflows
      • Trio/Duo Analysis
      • Association Analysis
      • LOH detection with an allele ratio spreadsheet
      • Import data from Agilent feature extraction software
      • Illumina GenomeStudio Plugin
        • Import gene expression data
        • Import Genotype Data
        • Export CNV data to Illumina GenomeStudio using Partek report plug-in
        • Import data from Illumina GenomeStudio using Partek plug-in
        • Export methylation data to Illumina GenomeStudio using Partek report plug-in
    • Tutorials
      • Gene Expression Analysis
        • Importing Affymetrix CEL files
        • Adding sample information
        • Exploring gene expression data
        • Identifying differentially expressed genes using ANOVA
        • Creating gene lists from ANOVA results
        • Performing hierarchical clustering
        • Adding gene annotations
      • Gene Expression Analysis with Batch Effects
        • Importing the data set
        • Adding an annotation link
        • Exploring the data set with PCA
        • Detect differentially expressed genes with ANOVA
        • Removing batch effects
        • Creating a gene list using the Venn Diagram
        • Hierarchical clustering using a gene list
        • GO enrichment using a gene list
      • Differential Methylation Analysis
        • Import and normalize methylation data
        • Annotate samples
        • Perform data quality analysis and quality control
        • Detect differentially methylated loci
        • Create a marker list
        • Filter loci with the interactive filter
        • Obtain methylation signatures
        • Visualize methylation at each locus
        • Perform gene set and pathway analysis
        • Detect differentially methylated CpG islands
        • Optional: Add UCSC CpG island annotations
        • Optional: Use MethylationEPIC for CNV analysis
        • Optional: Import a Partek Project from Genome Studio
      • Partek Pathway
        • Performing pathway enrichment
        • Analyzing pathway enrichment in Partek Genomics Suite
        • Analyzing pathway enrichment in Partek Pathway
      • Gene Ontology Enrichment
        • Open a zipped project
        • Perform GO enrichment analysis
      • RNA-Seq Analysis
        • Importing aligned reads
        • Adding sample attributes
        • RNA-Seq mRNA quantification
        • Detecting differential expression in RNA-Seq data
        • Creating a gene list with advanced options
        • Visualizing mapped reads with Chromosome View
        • Visualizing differential isoform expression
        • Gene Ontology (GO) Enrichment
        • Analyzing the unexplained regions spreadsheet
      • ChIP-Seq Analysis
        • Importing ChIP-Seq data
        • Quality control for ChIP-Seq samples
        • Detecting peaks and enriched regions in ChIP-Seq data
        • Creating a list of enriched regions
        • Identifying novel and known motifs
        • Finding nearest genomic features
        • Visualizing reads and enriched regions
      • Survival Analysis
        • Kaplan-Meier Survival Analysis
        • Cox Regression Analysis
      • Model Selection Tool
      • Copy Number Analysis
        • Importing Copy Number Data
        • Exploring the data with PCA
        • Creating Copy Number from Allele Intensities
        • Detecting regions with copy number variation
        • Creating a list of regions
        • Finding genes with copy number variation
        • Optional: Additional options for annotating regions
        • Optional: GC wave correction for Affymetrix CEL files
        • Optional: Integrating copy number with LOH and AsCN
      • Loss of Heterozygosity
      • Allele Specific Copy Number
      • Gene Expression - Aging Study
      • miRNA Expression and Integration with Gene Expression
        • Analyze differentially expressed miRNAs
        • Integrate miRNA and Gene Expression data
      • Promoter Tiling Array
      • Human Exon Array
        • Importing Human Exon Array
        • Gene-level Analysis of Exon Array
        • Alt-Splicing Analysis of Exon Array
      • NCBI GEO Importer
    • Webinars
    • White Papers
      • Allele Intensity Import
      • Allele-Specific Copy Number
      • Calculating Genotype Likelihoods
      • ChIP-Seq Peak Detection
      • Detect Regions of Significance
      • Genomic Segmentation
      • Loss of Heterozygosity Analysis
      • Motif Discovery Methods
      • Partek Genomics Suite Security
      • Reads in RNA-Seq
      • RNA-Seq Methods
      • Unpaired Copy Number Estimation
    • Release Notes
    • Version Updates
    • TeamViewer Instructions
  • Getting Help
    • TeamViewer Instructions
Powered by GitBook
On this page
  • Advanced options
  • Trim Bases Task Details Page
  • Trim Bases Task Report Page
  • Trim Bases Output Files
  • References
  • Additional Assistance

Was this helpful?

Export as PDF
  1. Partek Flow
  2. User Manual
  3. Task Menu
  4. Pre-alignment tools

Trim bases

PreviousPre-alignment toolsNextTrim adapters

Last updated 7 months ago

Was this helpful?

The Trim bases task is used to trim bases from the 5'-end or 3'-end of the reads. The most obvious reason for Trim bases is to trim away poor quality bases from the read prior to alignment because these can potentially affect alignment rate.

The task allows user to trim reads in different ways (Figure 1), including:

  • Trim bases based on quality score

  • Trim bases from 3'-end

  • Trim bases from 5'-end

  • Trim bases from both ends

Trim bases from 5'-or 3'-end (Figures 2-3) allows a fixed number of bases to be trimmed away from the 5'- or 3'-end of the reads. These two functions are useful for when your read length is constant. This is not recommended if the read length is not constant, since good quality bases from shorter reads are likely trimmed away by these functions.

Trim bases from both ends (Figure 4) allows user to keep only bases from a fixed start and end position of the reads. This is particularly useful if poor quality bases are observed on both ends of the read. So instead of performing trim bases successively from the 5'- and 3'-end, the trim bases will only be performed once by trimming from both ends.

Trim bases based on quality score (Figure 5) is probably the most useful function to trim poor quality bases from the 5'- or 3'-ends of reads. This function allows dynamic trimming of bases depending on quality score. The trimming can be done from either 5'-end, 3'-end or both ends of the reads. The function evaluates each base from the end of the read and trims it away until the last base has a quality score greater than the specified threshold. For an extensive evaluation of read trimming effects on Illumina NGS data analysis, see Del Fabbro et. al. [1].

Advanced options

In some cases, the reads that result from base trimming can have very short read lengths and thus are not recommended for alignment. Thus, Partek® Flow® Flow provides the option to set a Min read length after base trimming. This discards reads that are shorter than the set length.

Also, reads could have a high percentage of N's or ambiguous bases. Thus, the Max N setting is available to discard reads with %Ns higher than the set threshold

The Quality encoding option refers to the Phred quality score encoded within the FASTQ input file. The list of available options are: Phred+33, Phred+64, Solexa+64 and Integers. Selecting Auto-detect will determine whether the quality encoding is Phred+33 or Phred+64. For Solexa data, you will need to select Solexa+64. For most of datasets, auto-detect option works very well with a few exception cases where the base quality score falls into the grey zone (ambiguous zone) of Phred+33 and Phred+64 score. However, if the quality-encoding scheme is known, we recommend to selecting the encoding format directly from the quality encoding list.

Figure 6 shows the options available for all the different selection of Trim bases function. Note the default Min read length is 25bp. For micro RNA sequencing data, this default Min read length needs to be set to a smaller value (we recommend 15) to account for mature microRNAs.

Trim Bases Task Details Page

The Task Details page for Trim bases can be accessed by selecting the task node Trim bases, and subsequently selecting Task Details from the Task results section. In the Task details page, several sections are available:

  • General task information: contains information such as the task name, owner, status, submitted time, start, end and duration of the task

  • Output Files: contains the description of each output file. If you roll-over your mouse cursor to the file name, you will get the exact location of the file on the server. If you click on the file name, you will have the option to view up to 999 lines of the raw data. You can also download the file from the server.

  • Input Files: contains the information of input files. This section lists down all the input files used in the Trim bases task.

  • Input Parameters: contains the parameters used for running Trim bases function. This section tells what option has been selected for the Trim bases task. It includes all the parameters used for the task, such as minimum read length, maximum percentage of N's base, quality encoding, quality score threshold (if applicable) and how trimming is performed.

  • Command Lines: shows the commands used for running Trim bases function by the software Partek Flow

Trim Bases Task Report Page

The Trim bases Task Report page can be accessed by selecting either the Trim bases task node or Trimmed reads data node and then selecting the Task Report from the Task results section of the context sensitive menu. There is a link at the bottom of the page to directly go to the Task Details page. The page displays the following components:

  • Summary table: gives the total number of reads in each sample, the total number of reads trimmed (i.e. with at least one base trimmed from the read), total number of reads removed (due to Min read length and Max N parameters), the average number of bases trimmed per read, the average read quality before trim bases and finally the average read quality after trim bases.

  • Stacked bar-chart: shows percentage of untrimmed reads, trimmed reads and removed reads are shown in a stacked bar-chart to compare all the samples.

  • Average base quality score per position of trimmed reads: shows the average base quality score at each position of the trimmed reads for all samples in the project.

Trim Bases Output Files

The Trim bases function produces trimmed unaligned reads which is named as Trimmed Reads data node. The Trimmed Reads node will have the "trimmed" word appended to the filename. The Trimmed Reads data can be downloaded by selecting the Trimmed Reads node and then select Download data from the context sensitive menu. However, if you have access to the Partek Flow server, you can go to the Task Details page and identify the location of the output files from the Output Files section as described on the Trim Bases Task Details section above. The Trimmed Reads data node will have the same format as the raw data.

References

  1. Del Fabbro C, Scalabrin S, Moragante M, Giorgi FM. An extensive evaluation of read trimming effects on Illumina NGS data analysis. PLoS ONE. 2013; 8(12): e85024.

Additional Assistance

If you need additional assistance, please visit to submit a help ticket or find phone numbers for regional support.none;">43rates

our support page
Figure 1. Select a Trim mode to trim poor quality bases from reads
Figure 2. Trim bases from 5'-end
Figure 3. Trim bases from 3'-end
Figure 4. Trim bases from both ends
Figure 5. Trim bases based on quality score
Figure 6. Trim bases options. A) Trim from 3'-end; B) Trim from 5'-end; C) Trim from both ends; D) Trim based on base quality score