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tRF&tiRNA Research Tools

rtStar™ tRF&tiRNA Pretreatment & First-Strand cDNA Synthesis Kit — Prepare tRF&tiRNA Termini and Remove Modification Barriers

The rtStar™ tRF&tiRNA Pretreatment Kit prepares tRF & tiRNA samples before the cDNA synthesis used for qPCR. The kit generates terminal 3′-OH and 5′-P ends for adapter ligation by removing 3′-cP and phosphorylation of 5′-OH often present in tRF and tiRNA fragments, and internal m1A, m1G, and m3C are demethylated for efficient cDNA reverse transcription.

Pretreatment + first-strand cDNA synthesis · precursor discrimination · magnitudes of sensitivity gain

Overview

The complete solution for tRF&tiRNA qPCR sample preparation

The rtStar™ tRF&tiRNA First-Strand cDNA Synthesis Kit converts the pretreated tRF and tiRNA fragments into cDNA for qPCR reaction. The method sequentially ligates the 3′ Adaptor to the 3′ ends of the RNAs and the 5′ Adaptor to the 5′ ends of the RNAs.

The kit efficiently removes internal modifications to ensure the proceeding of reverse transcriptase during cDNA synthesis, efficiently removes terminal modifications to ensure terminal 3′-OH and 5′-P ends suitable for the subsequent adapter ligation, and is capable of distinguishing tRFs & tiRNAs from their precursors.

What does this kit do?

The kit prepares tRF & tiRNA samples for qPCR cDNA synthesis in two parts: pretreatment generates terminal 3′-OH and 5′-P ends for adapter ligation and demethylates internal m1A, m1G, and m3C; the first-strand cDNA synthesis kit then ligates 3′ and 5′ adaptors and converts the fragments into cDNA.

Service at a Glance

Standard catalog products

Product NameCatalog No.SizePrice
rtStar™ tRF&tiRNA Pretreatment KitAS-FS-00512 reactions
rtStar™ First-Strand cDNA Synthesis Kit (3′ and 5′ adaptor)AS-FS-00312 reactions

Benefits

Key advantages of the rtStar™ tRF&tiRNA kit

⚗️

Efficient Internal Modification Removal

Efficient removal of internal modifications (m1A, m1G, m3C) to ensure the proceeding of reverse transcriptase during cDNA synthesis, whereas the regular cDNA synthesis method does not.

🔧

Terminal Preparation

Efficient removal of terminal modifications to ensure terminal 3′-OH and 5′-P ends suitable for the subsequent adapter ligation.

🎯

Precursor Discrimination

Capable of distinguishing tRFs & tiRNAs from their precursors.

📈

Dramatic Sensitivity Gain

Magnitudes of increase in tRF&tiRNA detection sensitivity, quantification accuracy, and assay discriminating power with the treated compared with untreated samples.

🔗

System-Optimized

Optimized for the nrStar™ tRF&tiRNA PCR Arrays and Pre-designed Primer Sets.

Background

Why tRF&tiRNA sample preparation needs special handling

tRFs and tiRNAs, generated through precise biogenesis processes from tRNA, perform many biological functions as small noncoding RNAs and are associated with many diseases and conditions. However, the characteristics of tRFs and tiRNAs pose special challenges for their expression profiling.

Varying with their particular sources and endoribonuclease cleavages, tRFs and tiRNAs contain many distinct internal modifications and modified termini. While some tRFs and tiRNAs may inherit methylation modifications (such as m1A) and aminoacylated termini from their source tRNAs, tiRNAs generated by angiogenin often have 5′-OH and 3′-cyclic phosphate (cP) modifications at the cleavage site.

Many current standard cDNA library construction methods, particularly those that target small noncoding RNAs, include adaptor ligation steps in which 5′ and/or 3′ oligonucleotide adaptors are ligated to the ends of the RNA molecule. Because 5′-P and 3′-OH at the ends of the RNA substrate are required for adaptor ligation reactions, standard cDNA library construction methods are inadequate for tRF and tiRNA. Importantly, post-transcriptional modifications within the tRF and tiRNA sequence, such as m1A and m3C, also greatly interfere with reverse transcription for cDNA synthesis. In order to efficiently and accurately analyze tRF and tiRNA by qPCR methods, these obstacles must be removed first.

Kit Workflow

From RNA to tRF&tiRNA cDNA in four steps

1

RNA Input

Purified total RNA containing small RNAs is used as input, with quality and quantity assessment.

2

Pretreatment

The rtStar™ tRF&tiRNA Pretreatment Kit generates terminal 3′-OH and 5′-P ends (removing 3′-cP and phosphorylating 5′-OH) and demethylates internal m1A, m1G, and m3C.

3

Adaptor Ligation & cDNA Synthesis

The rtStar™ First-Strand cDNA Synthesis Kit sequentially ligates the 3′ Adaptor to the 3′ ends and the 5′ Adaptor to the 5′ ends of the RNAs, then synthesizes cDNA.

4

qPCR Detection

cDNA is used for qPCR with the nrStar™ tRF&tiRNA PCR Arrays or Pre-designed Primer Sets.

Bioinformatics & Deliverables

Product specifications and documentation

This kit is optimized for the nrStar™ tRF&tiRNA PCR Arrays and Pre-designed Primer Sets, and Arraystar is not able to advise on other applications. Manuals are provided for both the pretreatment kit and the first-strand cDNA synthesis kit.

Standard Deliverables

Research Applications

Where the rtStar™ tRF&tiRNA kit is used

tRF&tiRNA qPCR Arrays

Optimized for the nrStar™ tRF&tiRNA PCR Arrays for high-specificity tRF/tiRNA profiling.

Pre-designed Primer Sets

Pairs with rtStar™ Pre-designed tRF&tiRNA Primer Sets for individual tRF/tiRNA quantification.

Biomarker Discovery

Enables accurate tRF/tiRNA detection in biofluids, where they are highly enriched.

tRF&tiRNA Biology

Supports studies of RNA interference, mRNA stability regulation, apoptosis, and stress response.

Sample Requirements

Recommended RNA input for rtStar™ tRF&tiRNA kit projects

RNA Amount & Quality

  • Total RNA input: > 5 µg per sample is recommended for tRF&tiRNA qPCR array projects (official Arraystar recommended minimum for the entire experiment in a single attempt, including sample QC).
  • Purification: TRIzol / RNA precipitation or an RNA isolation kit. Because tRF&tiRNA are < 200 nt, use a kit specified to retain small RNAs (e.g. Qiagen miRNeasy).
  • Concentration: > 20 ng/µL by Nanodrop; OD260/280 ~2.0 (acceptable 1.7–2.1); OD260/230 > 1.8.
  • Integrity: sharp 18S/28S rRNA bands by gel, or RIN > 7.0 by Bioanalyzer (serum/plasma/exosome/FFPE RNA exempt).
  • DNase treatment: required because the sample is used for qPCR.

Shipping Instructions

  • Ship RNA in nuclease-free water (> 20 ng/µL), freeze-dried, or in ethanol; store at −80 °C or in liquid nitrogen.
  • Use nuclease-free certified, screw-cap 1.5 mL microtubes; seal caps with Parafilm; place tubes in a plastic bag.
  • Use 10 kg dry ice as refrigerant; include a signed Project Form and the sample list.
  • Ship to: Arraystar Inc., 9430 Key West Avenue #128, Rockville, MD 20850, USA. Contact us before shipping.

FAQ

Common questions about the rtStar™ tRF&tiRNA kit

Why do tRFs&tiRNAs need special pretreatment?
tRFs and tiRNAs contain distinct internal modifications and modified termini that block standard cDNA synthesis. tiRNAs often have 5′-OH and 3′-cyclic phosphate at cleavage sites, while adaptor ligation requires 5′-P and 3′-OH ends; internal modifications such as m1A and m3C also interfere with reverse transcription. The pretreatment kit resolves both obstacles.
What does the pretreatment step do?
The rtStar™ tRF&tiRNA Pretreatment Kit generates terminal 3′-OH and 5′-P ends for adapter ligation by removing 3′-cyclic phosphate and phosphorylating 5′-OH, and demethylates internal m1A, m1G, and m3C modifications. This ensures efficient cDNA reverse transcription during the subsequent first-strand synthesis step.
How does the kit distinguish tRFs&tiRNAs from their precursors?
The first-strand cDNA synthesis step sequentially ligates the 3′ Adaptor to the 3′ ends and the 5′ Adaptor to the 5′ ends of the RNAs. Combined with junction-targeting primers in the nrStar™ tRF&tiRNA PCR Arrays, this is capable of distinguishing tRFs & tiRNAs from their tRNA or pre-tRNA precursors.
What improvement can I expect?
The kit delivers magnitudes of increase in tRF&tiRNA detection sensitivity, quantification accuracy, and assay discriminating power with the treated compared with untreated samples, when used with the nrStar™ tRF&tiRNA PCR Arrays or Pre-designed Primer Sets as recommended by Arraystar for best results.
Which products is this kit optimized for?
The kit is optimized for the nrStar™ tRF&tiRNA PCR Arrays and Pre-designed Primer Sets. Arraystar is not able to advise on other applications; for other RNA classes, please contact our technical team for guidance on the appropriate product and workflow.
What is the recommended RNA input?
We recommend more than 5 µg of total RNA per sample for tRF&tiRNA qPCR array projects — the official Arraystar recommended minimum for the entire experiment in a single attempt, including sample QC. Supplying twice the recommended minimum helps avoid project delays. DNase treatment is required for qPCR.

Selected Publications

Featured Client Publications Using rtStar™ tRF&tiRNA Pretreatment

  1. Wang C, et al. tiRNA-HAR contributes to ischemic myocardial injury via facilitating HuR-mediated stability of P53. Translational Research, 2025. PMID: 40252996
  2. Wang X, et al. Dysregulation of pseudouridylation in small RNAs contributes to papillary thyroid carcinoma metastasis. Cancer Cell International, 2024. PMID: 39402656
  3. Deng Z, et al. tRNA-Derived Fragment tRF-5009A Regulates Autophagy and Degeneration of Cartilage in Osteoarthritis via Targeting mTOR. Oxidative Medicine and Cellular Longevity, 2022. PMID: 36035226
  4. Ma C, et al. tRNA-derived fragment tRF-1020 ameliorates diabetes-induced retinal microvascular complications. Journal of Cellular and Molecular Medicine, 2022. PMID: 36128646
  5. Zhang G, et al. Genome-Wide Repertoire of Transfer RNA-Derived Fragments in a Mouse Model of Age-Related Cataract. Current Eye Research, 2022. PMID: 35930684
  6. Ying X, et al. METTL1-m7G-EGFR/EFEMP1 axis promotes the bladder cancer development. Clinical and Translational Medicine, 2021. PMID: 34936728
  7. Tao EW, et al. A specific tRNA half, 5′tiRNA-His-GTG, responds to hypoxia via the HIF1a/ANG axis and promotes colorectal cancer progression by regulating LATS2. Journal of Experimental & Clinical Cancer Research, 2021. PMID: 33588913
  8. Zhu L, et al. The tRNA-derived fragment 5026a inhibits the proliferation of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway. Stem Cell Research & Therapy, 2021. PMID: 34294122

Ready for Accurate tRF&tiRNA Detection?

The rtStar™ tRF&tiRNA Pretreatment & First-Strand cDNA Synthesis Kit removes terminal and internal modification barriers for accurate qPCR — request a quote today.