Thermo Fisher RNAi & RNA Reagents for Reliable Gene Silencing

Thermo Fisher’s RNAi and RNA reagents help you silence target genes with confidence—whether you need rapid, reversible knockdown via siRNA/miRNA or long-term suppression with shRNA workflows. This Collection curates proven product families, popular controls, and RNAi-optimized transfection tools. As a distributor, Iright can source a wide range of Thermo Fisher options and support you from selection to validation.

Shop by Application: Gene Knockdown, miRNA Function & Stable shRNA

Choosing by application shortens your path to data. Start with the biological question—acute, reversible knockdown, endogenous miRNA modulation, or long-term suppression—then match it to the right chemistry and delivery. The cards below guide you to suitable reagent families and typical validation endpoints.

• Acute gene knockdown (siRNA): Rapid, reversible mRNA silencing for target validation and phenotype screens.

• miRNA gain/loss of function: Use mirVana™ mimics (up-regulate) or inhibitors (down-regulate) to probe endogenous regulation.

• Stable knockdown (shRNA/lentiviral): Long-term studies and clonal work where persistent suppression is required.

• Hard-to-transfect cells: Prioritize Lipofectamine™ RNAiMAX for high efficiency with low cytotoxicity in RNAi applications.

siRNA, miRNA, shRNA & RNAi Transfection—Product Families & Use Cases

Each family addresses different experimental constraints. siRNA enables fast, tunable knockdown; miRNA tools model endogenous post-transcriptional control; shRNA supports durable effects; and RNAi-dedicated transfection reagents maximize delivery of small RNAs while minimizing toxicity. The short notes below map common use cases to product lines.

• Silencer™ Select siRNA: Enhanced specificity chemistry; pair with positive/negative controls for method setup and QC.

• mirVana™ miRNA mimics/inhibitors: Bench-tested controls and broad titer options to calibrate miRNA perturbations.

• shRNA/viral formats: Choose when you need weeks-to-months suppression or selection-based workflows.

• Lipofectamine™ RNAiMAX: RNAi-optimized transfection reagent available in multiple pack sizes for screening to scale-up.

How RNAi Works: RISC Loading, mRNA Silencing & Off-Target Basics

RNA interference uses double-stranded small RNAs to program the RISC complex to complementary mRNAs, promoting cleavage or translational repression. siRNA duplexes typically induce robust, sequence-directed knockdown; miRNA mimics/inhibitors model endogenous regulation. Compared with gene knockout, RNAi is reversible and dose-tunable, which is useful for essential genes and temporal studies.

Choose the Right Reagent: siRNA vs miRNA vs shRNA for Your Cell Model

Start with your biological objective and cell line constraints, then align to the appropriate format and delivery. Consider serum conditions, density at transfection, toxicity thresholds, and readout windows. When in doubt, pilot a small matrix—dose × cell density—using validated controls to lock in conditions before scaling.

• Need fast, reversible suppression? Use Silencer™ Select siRNA with non-targeting and positive controls to baseline performance.

• Interrogate endogenous regulation? Pick mirVana™ mimics (gain) or inhibitors (loss) with matched negative controls and confirm by qPCR/protein.

• Require long-term effects or selection? Move to shRNA/lentiviral approaches and plan for clonal verification.

• Difficult cells? Use Lipofectamine™ RNAiMAX, titrating reagent and RNA amounts to minimize cytotoxicity while maintaining efficiency.

Popular Reagents & Controls: Silencer Select, mirVana & Lipofectamine RNAiMAX

Below are frequently chosen Thermo Fisher items that anchor most RNAi workflows. Use negative controls to estimate baseline effects, positive controls to verify pathway responsiveness, and RNAiMAX for delivery.

RNAi Workflow & Validation: Transfection → qPCR/Western → Phenotype

Plan for an optimization pass before your main run. Define confluence and serum conditions at transfection, pre-mix complexes carefully, and sample at multiple windows—24, 48, and 72 hours are common for mRNA/protein kinetics. Use qPCR for early signal and protein assays for functional confirmation, then capture phenotype with imaging or viability readouts.

Suggested checklist (abbreviated):

• Plate cells for ~70–80% confluence at transfection; confirm mycoplasma-free status.

• Complex RNAiMAX with siRNA/miRNA at recommended ratios; include non-targeting control and a GAPDH positive control for QC. 

• Harvest RNA at 24–48 h for qPCR; collect protein at 48–72 h for Western/ELISA.

• Record phenotype (e.g., proliferation, apoptosis markers) and monitor cytotoxicity; titrate reagent and RNA if viability drops.

Troubleshooting pointers:

• Low knockdown: Re-titrate siRNA dose and RNAiMAX volume; verify target sequence and cell density.

• High toxicity: Reduce reagent/RNA amounts, switch to serum-compatible conditions, shorten exposure.

• Off-target effects: Use Silencer Select chemistry and multiple independent siRNAs; validate with rescue where possible.

RNAi FAQs: Knockdown Tips, Controls, Troubleshooting

A short FAQ reduces friction for first-time users and speeds repeatable setup. Use it to anchor internal links to product families, controls, and accessory kits elsewhere in the catalog.

Q1. siRNA, miRNA mimic, or inhibitor—how should I choose?
Start from the question: acute target knockdown (siRNA), endogenous pathway modeling (miRNA mimic/inhibitor), or durable suppression (shRNA). Consider readout timing and whether reversibility is desired.

Q2. Which controls are essential?
Always run a non-targeting negative control and, where possible, a positive control (e.g., GAPDH siRNA) to confirm transfection/assay responsiveness.

Q3. What’s special about Lipofectamine RNAiMAX for RNAi?
It’s formulated specifically for small RNA delivery, balancing high efficiency with low toxicity across many lines; it’s available from small screening to 15 mL scale.

Q4. When should I measure knockdown?
mRNA reduction is often visible by 24–48 h; protein changes may lag to 48–72 h, depending on turnover. Validate the optimal window in a pilot.

Talk to Iright

If you need help mapping your application to the best mix of Silencer™ Select siRNA, mirVana™ controls, or Lipofectamine™ RNAiMAX, talk to Iright. We can recommend starter bundles (siRNA/miRNA + controls + transfection), align pack sizes to your throughput, and arrange fast delivery for your lab schedule. Share your cell model and readouts—we’ll help you finalize conditions and move from hypothesis to clean, reproducible knockdown.