Programming the Genome


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There are roughly 19,000 naturally occurring protein-coding genes in the human genome. In addition, the genome harbors sequences for numerous microRNAs and other functional, non-coding RNAs. To understand the activities of these genes within cells, scientists require tools to turn them on or off at will, as well as ways to introduce new gene sequences, change endogenous genes or remove genes entirely. At Mirus Bio, our scientific interests have long been focused on methods to program cells using nucleic acids. As such, one of our primary goals is to understand how recombinant and synthetic DNA and RNA can be leveraged to create new sets of instructions for controlling and understanding cell biology. With a dedicated team of biologists and chemists and more than 20 years of demonstrated expertise, Mirus has become the leader in gene delivery technologies. Our vision is to provide the most effective delivery methods that enable researchers to add, delete or modify genes at will.

Databases such as those provided by The Human Genome Project, provide scientists with a list of sequences, but the functions of these genetic elements remain largely unknown. The next step in advancing our understanding of cell biology is determining how these snippets of code work together in a coordinated fashion to create the molecular circuitry that controls living cells. At its core, gene delivery is the process of downloading a set of commands into a living cell. With our increasing understanding of how gene-regulatory circuits work combined with advances in genetic tools and nucleic acid delivery methods, we are ushering in a new era in science where we can readily apply engineering principles to biology. With the right gene delivery tools at their disposal, scientists now have unprecedented genome control at their fingertips.

Plus Minus Delta - Add


Chemical transfection, electroporation and transduction with viruses such as lentivirus and AAV can achieve high levels of gene expression.

Plus Minus Delta - Delete


Gene expression can be reduced with siRNA, miRNA and antisense oligonucleotides, or eliminated with CRISPR genome editing.

Plus Minus Delta - Modify


Genome editing with CRISPR allows for precise and targeted genome modification such as tagging, replacing or truncating endogenous genes.


Any delivery method

A Toolkit for Molecular Cell Biology

Whether it be for overexpression, knockdown or gene editing, nucleic acid delivery is a central technique in molecular cell biology. Mirus Bio provides a comprehensive set of tools for introducing nucleic acids to cells that includes advanced solutions for chemical transfection, viral transduction and electroporation .

Chemical Transfection

Chemical carriers such as our TransIT® Transfection Reagents represent the most straightforward and widespread tools for gene delivery experiments in mammalian cells. Chemical transfection experiments follow a simple workflow and provide high efficiency nucleic acid delivery for the most commonly used cells as well as many hard-to-transfect cell lines.

Viral Transduction

Transduction is the deliberate introduction of nucleic acids to cells via viral vectors such as lentiviruses, adenoviruses and adeno-associated viruses (AAV). Viruses harness the power of millions of years of evolutionary refinement to efficiently deliver genes to cells. Despite many advances in non-viral delivery methods, certain cell types and protocols require the potency of engineered viruses. Our TransIT®-Lenti Transfection Reagent provides high efficiency transfection of lentivirus packaging vectors to achieve maximal virus titers in HEK-293 cells, and our flashBAC™ Baculovirus Expression Systems offer high yield protein production in insect cells.


Electroporation is a simple and rapid gene delivery method that utilizes a short, high-voltage electrical pulse to create transient openings in the cell membrane in order to allow loading of desired cargoes into the cell. Electroporation achieves efficient delivery of nucleic acids in most cell types with minimal optimization. Ingenio® Electroporation Kits offer a simple, broad spectrum solution for gene delivery and are compatible with most conventional electroporation devices.


Any cell type

Broad Spectrum Delivery

The best starting point for gene delivery is a broad spectrum reagent which performs well across many cell types. We offer several broad spectrum formulations, each providing high efficiency and low toxicity chemical transfection to suit researchers individual experimental needs. Our highest performance broad spectrum solution, TransIT-X2® Dynamic Delivery System, leverages our latest advances in polymer chemistry for delivery of plasmid DNA, siRNA/miRNA and CRISPR/Cas9 components. Our TransIT®-2020 Transfection Reagent is a high performance reagent for DNA delivery in many cell types including primary and difficult to transfect cells. Our original TransIT®-LT1 Transfection Reagent remains one of the gentlest DNA transfection reagents on the market, showing little or no toxicity in even the most delicate cell types.

Cell-Type-Specific Reagents

Certain cell types and cell culture conditions require specific formulations for efficient transfection. OurTransIT-PRO® Transfection Kit is specifically optimized to deliver DNA to suspension HEK 293 and CHO cells for manufacturing antigens, antibodies and candidate biologics, and our CHOgro® Expression System further supports this workflow with CHOgro® Expression Media and supplements to promote high density CHO cell growth. Immune cells such as RAW 264.7 and Jurkat are typically recalcitrant to chemical transfection and only respond to specific formulations such as our TransIT®-Jurkat Transfection Reagent. We have also developed specialized reagent formulations for breast cancer cell types, keratinocytes, laboratory workhorse cell lines such as adherent HeLa, CHO, HEK and more. Explore our full offering of transfection reagents here >>

Reagent Agent®

Finding the right conditions and transfection reagent for various combinations of cell types and nucleic acids can be a daunting task. To simplify this process, we designed the Mirus Reagent Agent® Transfection Database to serve as virtual assistant for planning transfection experiments. Simply enter the cell type and nucleic acid to be used in your experiment, and Reagent Agent® will return detailed methods and reagent suggestions. Our algorithm pulls from in-house experimental data, customer feedback and cited use of our transfection reagents, then prioritizes these results to provide users with the most relevant suggestions and data. Reagent Agent® continues to get smarter as our Research and Support Scientists test and optimize conditions for various cell types, annotate peer-reviewed publications and add new feedback to the database.


Any nucleic acid

DNA Delivery

Plasmid DNA delivery remains one of the most powerful, versatile and efficient gene delivery methods for various applications ranging from protein expression to gene silencing with shRNA. Our broad spectrum reagents, TransIT-X2® Dynamic Delivery System, TransIT®-2020 Transfection Reagent and TransIT®-LT1 Transfection Reagent enable delivery to a wide range of cells with maximal cell viability. Electroporation with our Ingenio® Electroporation Solution extends this list to virtually any cell type with superior delivery efficiency using a single cost-effective and convenient solution.

siRNA and miRNA Delivery

One of the most widespread techniques for interrupting gene function is RNA interference (RNAi). Small interfering RNA (siRNA) is a molecular tool used to induce RNAi for transient downregulation of gene expression in mammalian cells. Structurally, siRNAs are double-stranded and range from 20 to 24 bp in length with two overhanging nucleotides on the 5' and 3' ends. Naturally occurring microRNAs (miRNAs) are 22 nucleotide RNAs that regulate mRNAs in animal and plant cells. As with siRNA, miRNA can be delivered to cells to regulate gene expression. Transfection experiments with siRNA often involve cytoplasmic delivery of synthetic duplex RNA molecules designed to target a specific mRNA. One of the key distinctions between siRNA and miRNA is target specificity; synthetic siRNAs are typically engineered to target a single mRNA sequence, whereas miRNAs often have multiple targets. Therefore, in contrast to siRNA delivery experiments where a single gene may be targeted with high specificity, miRNA transfection experiments can be analogous to flipping a switch in order to effectively turn entire gene regulatory networks on or off. As with most cell biology experiments aimed at modifying gene function, the success of RNAi is dependent on efficient delivery. Mirus offers three distinct reagent formulations for efficient gene knockdown in a wide range of cell types: TransIT-X2® Dynamic Delivery System, TransIT-siQUEST® Transfection Reagent and TransIT-TKO® Transfection Reagent.

CRISPR Guide RNA and Cas9 RNP Delivery

The CRISPR/Cas9 genome editing platform relies on a guide RNA to direct the Cas9 endonuclease to the target site. Guide RNA delivery can be accomplished by several means. Guide RNA can be expressed off of plasmid utilizing an RNA polymerase III promoter such as the U6 promoter, or the guide RNA can be delivered as a single or two-part synthetic oligonucleotide. Many researchers utilize two-part guide RNAs consisting of a CRISPR RNA (crRNA) which defines target specificity, and a trans-activating crRNA (tracrRNA) which remains constant from one experiment to the next. Thus, this flexible approach only requires designing the crRNA when re-targeting different genomic loci. Our TransIT-X2® Dynamic Delivery System and TransIT®-mRNA Transfection Kit efficiently deliver single or two-part gRNA oligos. TransIT-X2® Dynamic Delivery System also efficiently delivers Cas9 protein and guide RNA as a ribonucleoprotein (RNP) complex. For more information on how the CRISPR/Cas9 system works, visit our CRISPR Application Page.

mRNA Delivery

mRNA transfection is an attractive alternative to DNA transfection for several reasons: Messenger RNA does not require transport to the nucleus, does not require transcription and leads to rapid gene expression following transfection. DNA-free transfection methods are also advantageous due to the fact that there is no risk of insertional mutagenesis. The rapid bursts of expression associated with mRNA delivery are often ideal in genome editing experiments where long-term expression is avoided in order to mitigate off-target effects. Our TransIT®-mRNA Transfection Kit efficiently delivers mRNA as well as longer viral RNAs.

Oligonucleotide Delivery

Antisense oligonucleotides (ASOs) are routinely used for modulation of gene expression. For example, ASOs can be designed to block the function of miRNAs in a sequence-specific manner. Oligonucleotide delivery is also becoming increasingly important for achieving precise genomic insertions following targeted cleavage by Cas9. Our TransIT®-Oligo Transfection Reagent has been used to deliver a wide range of oligonucleotides including phosphodiester DNA, phosphothioate DNA (sDNA), phosphothioate RNA (sRNA), 2'OMe RNA, 2'OMe RNA/sDNA Chimerics, Morpholino/DNA duplexes, siRNA and miRNA.


Optimal delivery systems for molecular and cell biology applications

Advances in genetic tools and nucleic acid delivery technology have dramatically expanded the toolkit available to researchers for investigating molecular cell biology. Mirus offers delivery methods for any cell type and any nucleic acid to support researchers who are looking for answers in CRISPR genome editing, stem cell research, biotherapeutics, virus production and more. By building the most advanced technologies for nucleic acid delivery, we enable scientists to more effectively focus on their research, their results and their discoveries.


We focus on gene delivery so you can focus on what matters to you: Results.