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BacMam Expression System

Gene expression in mammalian cells

BacMam is a modified baculovirus vector which efficiently transduces most mammalian cells – including primary cultures, cell lines, and iPSC derived cells. Researchers in life science and drug discovery have used BacMam for years to transiently deliver target receptors, genetically-encoded biosensors and other constructs in their cells of interest.

Montana Molecular’s biosensors, receptors, and optogenetic tools are packaged in BacMam because of its many benefits. Here we explore these benefits in an effort to explain why so many researchers are switching from plasmid transfection, stable cell lines and other viral vectors to using the BacMam system in their cells of choice.

Consistent, Titratable Expression

BacMam provides a very even level of expression from cell to cell and plate to plate, providing near stable-line consistency in a transient model. Expression can be easily titrated to a level that is suitable to the experiment and sensor being used. Receptors packaged in BacMam, for example, can be titrated to express at near endogenous levels. Experiments are more consistent, repeatable, and reliable.

DAG sensor expressing in HEK293T cells, comparing BacMam transduction (left) and plasmid transfection (right)

Expression in Difficult Cell Types and Primary Cultures

Our BacMam-packaged sensors have been used successfully in many primary and iPSC-derived cells including neurons, pancreatic islets, and cardiomyocytes. BacMam is a great choice for examining these interesting, disease-relevant cells because of its low toxicity and effective expression which can last for several days. Let us know if you have questions about your specific cell type, and see examples on our Publications page!

cADDis cAMP sensor expressing in Peri.4u iPSC derived peripheral neurons from Ncardia. Wide Field Fluorescence (left), Brightfield (right) 


“The transfection efficiency of the BacMam is excellent in hard-to-transfect cell lines like Calu-3s (>30-40% vs <10% with lipofectamine) and we can even achieve 5-10% transduction in macrophages, which are nearly impossible to transfect with cationic lipids.”

Dr. Rob Lee
University of Pennsylvania

“Expression in human islets is pretty superb, after 18 hours of incubation. An excellent probe!”

Dr. Andrei Tarasov
Oxford Center for Diabetes

“Assay is working beautifully with cardiomyocytes, showing a strong and immediate response.”

Dr. Kit Werley
Harvard University / Q-State Biosciences

Simple Workflow and Versatility

We also like BacMam for its ease of use. Simply add BacMam to your cells, incubate for 20-24 hours, and conduct your experiments. Incubation times of 48 hours can be helpful when expressing red fluorescent constructs. Separate viruses containing multiple constructs can be added at once, and an optional HDAC inhibitor can boost and maintain expression.

There are no extra incubation steps that you would have in a typical plasmid transfection and antibiotic can be present in the media. The same BacMam virus can also be used across a variety of cell types, no need to create multiple stable lines expressing the same receptor or construct..

Custom BacMam Production

Over the past few years, several researchers looked to improve on plasmid transfection efficiency by switching to BacMam. In response to their requests, we have developed a system to package GPCRs, ion channels, and other constructs in BacMam, providing an effective transfection alternative.

Cost Savings

BacMam is a low-cost alternative to plasmid transfection and creating stable cell lines. At ~$0.06 per well in a 96-well plate, it is a great alternative to transfection reagents such as lipofectamine ($0.08 per well, 96 well plate) and is considerably less of a commitment than purchasing or developing a stable cell line.

Large Payload

As BacMam has a nearly unlimited payload, we are able to add targeting sequences, cell-specific promoters, Cre-inducible systems, and more to our sensors to generate more precise tools for researchers. Our system allows for expression of larger constructs than plasmid transfection. Contact us for more information or to request tools that would be useful for your research.


BacMam: versatile gene delivery technology for GPCR assays:
Implementation of BacMam virus gene delivery technology in a drug discovery setting:
BacMam technology and its application to drug discovery:
BacMam recombinant baculoviruses in G protein-coupled receptor drug discovery:
New DAG and cAMP Sensors Optimized for Live-Cell Assays in Automated Laboratories:
Efficient generation of infectious recombinant baculoviruses by site-specific transposon-mediated insertion of foreign genes into a baculovirus genome propagated in Escherichia coli: