Contents
How do you know that your RNA-seq is stranded or not?
if you don’t know what sample prep protocol was used you have to map your reads to a reference genome and look at the sam flags in the bam file. If it is stranded, flags 83, 99, 147 and 163 have the same abundance but in stranded, 2 of these 4 will disappear when you look at either sense or antisense genes only.
What is stranded vs non stranded RNA-seq?
The read ambiguity in stranded RNA-seq arises only from overlapping genes transcribed from the same strand. In contrast, for non-stranded RNA-seq, the ambiguity arises from both the overlapping genes on the same strand and also from the opposite strands.
What is a stranded library?
Strand specific libraries allow you to identify the coding DNA strand for the transcript you sequence, while the strand information is lost in what you call regular library protocols. Neither polyA selection nor ribo-minus gives you information or limits to whether or not you will create a stranded library.
How do you analyze data in RNA sequencing?
For most RNA‐seq studies, the data analyses consist of the following key steps [5, 6]: (1) quality check and preprocessing of raw sequence reads, (2) mapping reads to a reference genome or transcriptome, (3) counting reads mapped to individual genes or transcripts, (4) identification of differential expression (DE) …
What will happen if RNA become double stranded?
RNA interference (RNAi) destroys mRNA that matches the sequence of previously-detected double-stranded RNA. The nuclease Dicer cuts double-stranded RNA into short segments (siRNA) that trigger the RNAi response. The target mRNA is degraded by proteins of the Argonaut family.
What will happen if double stranded RNA is produced during transcription?
In transcription, a portion of the double-stranded DNA template gives rise to a single-stranded RNA molecule. In some cases, the RNA molecule itself is a “finished product” that serves some important function within the cell.
How is hypothesis driven used in RNA Seq?
Hypothesis-driven Addresses a well thought-out quantifiable question Considerations: Library Construction: mRNA versus total RNA Single-end versus Paired-end Sequencing Sequencing Depth: quantifying gene-level or transcript-level expression Number of Replicates: statistical-power and ability drop a bad sample Reducing Batch Effects 2
What should be used to prepare RNA Seq library?
It’s a good idea to test some RNA from the same source as the sample intended for SOLiD sequencing at a range of times to identify the ideal incubation period for that sample. Note that you should make 1M Tris (pH 8.0) and 100 mM MgCl2 stocks and then make the fragmentation buffer solution as dilutions of these stocks.
What are the advances in RNA sequencing and analysis?
Recent advances in the RNA-Seq workflow, from sample preparation to library construction to data analysis, have enabled researchers to further elucidate the functional complexity of the transcription.
What should the sequencing depth be for RNA Seq?
I. Experimental Design: Sequencing Depth mRNA: poly(A)-selection Recommended Sequencing Depth: 10-20M paired-end reads (or 20-40M reads) RNA must be high quality (RIN > 8) Total RNA: rRNA depletion Recommended Sequencing Depth: 25-60M paired-end reads (or 50-120M reads) RNA must be high quality (RIN > 8)