RNA Interference (RNAi) with ThermoFisher Scientific

RNAi is a specific, potent, and highly successful approach for loss-of-function studies in virtually all eukaryotic organisms. At Thermo Fisher Scientific, we have developed two types of small RNA molecules that function in RNAi: short interfering RNA (siRNA) molecules and microRNAs (miRNA). Thermo Fisher Scientific offers Invitrogen products for RNAi analysis  in vitro and in vivo , including libraries for high-throughput applications. Your choice of tool depends on your model system, the length of time you require knockdown, and other experimental parameters.

siRNA Products

Note that prior to ordering, you must either link either an existing or a newly created ThermoFisher.com account to our portal. Please  download and follow the instructions for account set up.

Potent Gene Silencing

Silencer Select siRNA

Our product with the highest knockdown, fewest off-targets. Silencing guaranteed with 2/2 siRNAs. Libraries and custom designs available.

Silencer siRNA

Our most cost effective, guaranteed product.  2/3 siRNAs guaranteed to silence.  Moderate target specificity, Libraries and custom designs available.

Stealth RNAi siRNA

Our original RNAi product, with good knockdown, reduced off-targets.  2/3 siRNAs guaranteed to silence.  Custom designs available, libraries are not available.

miRNA Mimics & Inhibitors

Functional analysis of regulatory RNAs like microRNA (miRNA) can help decipher complex cellular processes in development and disease etiology.

We recommend mirVana mimics and inhibitors for anyone getting started with functional analysis of endogenous microRNA and looking for the latest advances in specificity and potency. Our Pre-miR and Anti-miR reagents remain relevant for ongoing studies that have benefited from these original product formats.

mirVana Mimics

Derived from miRBase v.22, these highly specific microRNA mimics are available in tubes, custom plated collections or whole genome libraries.

Chemical modifications prevent passenger strand entry into RISC.

Pre-miR Mimics

These legacy reagents, derived from miRBase v.15, are useful for ongoing studies that have used them in the past, and are available in individual tubes.

RNA duplexes mimic native microRNA.

mirVana Inhibitors

Derived from miRBase v.22, these inhibitors provide potent, long-lasting microRNA inhibition and are available in tubes, custom plated collections or who genome libraries.

Featuring patented designs and chemical modifications.

Anti-miR Inhibitors

These legacy reagents, derived from miRBase v.15, are useful for ongoing studies that have used them in the past, and are available in individual tubes.

Single-strand inhibitors of endogenous microRNAs.

Note that prior to ordering, you must either link either an existing or a newly created ThermoFisher.com account to our portal. 

Please  download and follow the instructions for account set up.

Our legacy ordering tool is still available for use, while you go through the account creation process for using the new ordering portal. Please complete the account set up process as soon as possible, so you are prepared for discontinuation of this tool.

RNA interference (RNAi) is the best way to effectively knock down gene expression to study protein function in a wide range of cell types. Traditional RNAi methods for gene knockdown in mammalian cells involved the use of synthetic RNA duplexes consisting of two unmodified 21mer oligonucleotides annealed together to form short/small interfering RNAs (siRNAs). Silencer® Select siRNA and Stealth RNAi™ siRNA improve upon these traditional duplexes by using proprietary chemical modifications to ensure better RNAi results. You can search and order the full list of siRNA and RNAi products from Life Technologies using the tool below. The tool will email us a shopping cart and we will place your order.  You will receive an email when the order has been placed.

Frequently asked questions

How do I set up a GRCF portal account with my favorite company? Is each company a different login?
  • For Dharmacon, if you have a current account, you do not need to create a new account. Simply starting on  our portal login page will associate your account with our portal. If you need to create an account, you can do so on the  registration pageOrders created on the Dharmacon portal create a quote which is emailed to the GRCF. The GRCF will place the orders by the end of the day. You will receive an email when the order has been placed.


  • For IDT, you must create a  portal specific account, but account set-up is instantaneous. Simply go to our portal and create a new account. Make sure you do not click anywhere else on the page prior to creating the account, or the web-site will lose the association with our portal. Once you have set up the account, you may place your order. When placing your first order on a newly created account, you will see incorrect pricing and shipping charges, but your bill will be correct.


  • For MilliporeSigma, you need to email us the following information:
  • Your name
  • Your email address
  • Your phone number
  • Your building and room number (for CoreStore deliveries)
  • Your PI’s name & email address
  • If you already have set up a GRCF account with MilliporeSigma, you may order using  this link.


  • Qiagen do not require an account. Shopping carts are emailed to the GRCF ( customorders@jhmi.edu) for ordering.


  • For ThermoFisher you must link your ThermoFisher account to the Dashboard.  Please download and follow these instructions.


How long does it take to activate my account?

Horizon Discovery and IDT are instantaneous. If you already have a Dharmacon direct account, you may simply login on our  portal page and your orders will be associated with the portal. If you already have a direct IDT account, you MUST create a new account by clicking “Set up new account” on our  portal page (without clicking anywhere else on the page.)

For MilliporeSigma, you must create an account and wait for an email indicating that the account is active. This may take up to two business days.

For ThermoFisher, you must link a ThermoFisher.com account to our portal. This process may take 24 hours.

Qiagen does not require an account. Orders are emailed to us and placed by the GRCF staff.

I already have an account set up with this company on their standard web-site. May I use that account?

For IDT and MilliporeSigma, you must create an account specific to the GRCF portal in order to take advantage of our pricing. Existing ThermoFisher accounts may be used, once they are linked to the portal. Prior Horizon Discovery (Dharmacon) accounts work, as long as you start on our  portal page.

Do I need a purchase order to place an order? Can I pay with an IO number?

On any of these sites, you will pay with your budget number. You do not need a credit card or a PO number from SAP. KKI customers should enter the last name of the PI on their grant or a KKI PO number. All customers (KKI and JHU) will be billed through iLab. JHU customers should check to make sure their budget numbers are active in iLab. Non-sponsored budget numbers must be added to iLab manually by following  these instructions.

When will I receive my items?

Standard oligo orders placed before noon from MilliporeSigma arrive the next business day. Standard oligo orders placed with IDT before 2 PM or ThermoFisher before 5 PM, will arrive in our office two business days after they are placed. Other items vary depending on the time it takes the manufacturer to ship. All items are available in Blalock 1004 the day they are received and will go out for delivery with the CoreStore the next morning.

Will you leave the order in my lab if no one is there?

No. Due to the sensitive nature of some of the items ordered through our portals, someone must be present in your lab for your order to be delivered.

May I pick up my order, even if I indicated I wanted delivery when I placed the order?

Yes. On a typical day, we receive the orders by 11:30 AM. Orders are available in Blalock 1004 from the time they arrive until we close at 4:30 PM. You may stop by and pick them up anytime during those orders. If you call ahead, please be prepared to tell us the order number and then name of the person placing the order. Orders are brought to the CoreStore early the following morning and set out for delivery.

If you know that you would like to pick up your order at the time you place your order, you may replace your building and room number with the words “Pick up” and we will contact you when the order arrives.  Pickup orders are placed in one of our lockers near the Blalock elevators and are available 24/7.

I order for more than one lab. How do I change where an order is being delivered?

You should create a separate ordering account for each lab to make sure that your orders are delivered to the correct location.