Recombinant DNA technology – Steps, Methods & Examples

Recombinant DNA technology is a biotechnology approach that has multidisciplinary applications and the potential to deal with important aspects of life, from health issues (e.g. by the means of recombinant antibodies) to food resources, and resistance to divergent adverse environmental effects. As genetic diseases are becoming more prevalent and agricultural areas are being reduced, the technology is gaining in importance in fields such as biochemistry and microbiology.

In this article, we will show you the steps in recombinant DNA production, methods and examples as well as outlooks in recombinant DNA technology. You can also find out more about the recombinant antibody production services by evitria.

• The Core Mechanism: Recombinant DNA (rDNA) technology enables the precise insertion of specific genetic sequences into host cells to produce targeted therapeutic proteins, including monoclonal and bispecific antibodies.
• The Mammalian Advantage: While early rDNA applications relied on bacterial hosts, modern therapeutic antibody expression relies almost exclusively on Chinese Hamster Ovary (CHO) cells to ensure native-like post-translational modifications (PTMs) and proper protein folding.
• Accelerating Drug Discovery: Advanced High-Throughput (HTP) transient transfection in CHO cells allows early-stage biotechs to physically validate hundreds of AI-designed antibody libraries in weeks, effectively mitigating runway risk.
• Clinical Scalability: Partnering with specialized expression platforms ensures >95% purity and ultra-low endotoxin levels (<1 EU/mg), bridging the gap from discovery to pre-clinical scale-up without the threat of batch-to-batch variability.

What is recombinant DNA technology? A definition

Recombinant DNA technology is the foundational engine of modern biotherapeutics. In the context of antibody discovery, this process involves the precise manipulation and isolation of genetic sequences encoding specific heavy and light chains.

These sequences are cloned into advanced expression vectors and subsequently transfected into a host cell system. While early recombinant milestones heavily utilized bacterial hosts like E. coli or yeast, the structural complexity of modern therapeutics—such as bispecifics and Fc-engineered formats—mandates the use of mammalian host systems.

Chinese Hamster Ovary cells are overwhelmingly preferred, as they alone can guarantee the correct folding, disulfide bond formation, and native-like glycosylation profiles required for human clinical efficacy.

There are several pros and cons of recombinant DNA. The disadvantages mainly relate to ethical or religious concerns in the commercialization of products containing recombinant DNA. But genetic engineering offers great opportunities in the research and production of innovative medical or therapeutic products.

History of recombinant DNA technology

While the structure of DNA was first determined in 1953, it wasn’t until the early 1970 years that the first recombinant DNA molecules were produced by the means of restriction enzymes. Paul Berg (Stanford) succeeded in proving the possibility to splice and to recombine genetic material in 1971.

Consequently, Stanley Cohen (Stanford) and Herbert Boyer (UC San Francisco) were able to cut and fuse specifically located DNA strands – a subsequently submitted patent for recombinant antibody technology was approved in 1980.^​1​ This has paved the way for further developments, from Fc-silenced abs to bispecific antibodies, wich are increasingly gaining attention in research and clinical applications.

Methods in recombinant technology

There are three different methods of producing recombinant DNA, namely transformation, non-bacterial transformation, and phage.

Transformation and non-bacterial transformation are similar processes, with the only difference being the use of bacteria such as E. Coli for the host. While the transformation process uses Escherichia coli to act as a biological framework, the non-bacterial method does not use any bacteria – as is evident in the name. Initially, one needs to choose which DNA segment to insert into the vector.

The second step is to cut that piece of DNA with a restriction enzyme (restriction endonuclease) and then ligate the DNA insert into the vector with DNA Ligase. The vector is inserted into a host cell, which has to be specifically prepared to take up the foreign DNA.

Phage introduction is the process of transfection, which is equivalent to transformation, but in this process, a phage is used instead of bacteria. The in-vitro process uses lambda or MI3 phages to produce phage plaques containing recombinants. By the means of different selection methods, the generated recombinant DNA can then be differentiated from non-recombinant DNA.

High-Throughput Transient Transfection in CHO Cells

For modern drug developers, the traditional method of generating stable cell lines is a time-prohibitive bottleneck during early discovery. To mitigate this runway risk, industry leaders utilize a High-Throughput antibody production service.

By temporarily introducing recombinant DNA into CHO cells without integrating it into the host genome, biotech firms can achieve rapid, parallel expression of up to several hundred antibody variants simultaneously. This allows AI-driven discovery platforms to move from in silico sequence generation to purified, assay-ready physical validation in as little as four weeks. Learn more about High-Throughput Antibody Production.

Steps in recombinant DNA production

Recombinant DNA is composed of sequences that are derived from different sources. The process to achieve this involves the following steps:

• Isolation of genetic material
• Cutting of DNA at specific locations
• Joining of DNA fragments by ligation and homopolymer tailing
• Insertion of DNA into the host cell
• Selection and screening of transformed cells

The last step can be achieved by an immunological method or nucleic acid hybridization, blue-white screening or insertional inactivationional inactivation.

Examples of Recombinant DNA Technology

Recombinant DNA technology examples span healthcare, agriculture, and the food industry. The first commercial healthcare product derived from rDNA was human insulin. Today, the technology is successfully applied to produce antibodies, vaccines, growth hormones, and industrial enzymes, which are among the many applications of recombinant proteins. Below are the most significant examples of recombinant DNA technology organised by sector.

5 Examples of recombinant DNA technology in the health sector

The first commercial healthcare product derived from rDNA was human insulin. Today, it is successfully applied to make new antibodies, vaccines (e. g. for Hepatitis B) and different protein production systems, for instance for insulin and human growth hormone.^​2​

The health sector offers the clearest and most impactful examples of recombinant DNA technology in action. Five landmark applications illustrate how rDNA has resolved historical bottlenecks in purity, scalability, and immunogenicity.

Here are 5 examples of rDNA technology in the health sector:

1. Insulin production

Insulin is a protein hormone produced in specific pancreatic cells and involved in the regulation of blood sugar levels. Before rDNA technology, diabetic patients relied on insulin extracted from animal sources, which carried risks of impurities, immune reactions, and supply shortages.

Although Frederick Sanger elucidated the nucleotide sequence of human insulin in the 1950s, it took another two decades until restriction endonucleases and plasmid techniques were sufficiently refined to reprogram bacterial cells to produce human insulin at pharmaceutical quality and industrial scale.

Because insulin consists of two protein chains linked by disulfide bonds, the process had to be transferred into more complex host organisms such as yeast to yield properly folded, glycosylated product. Human insulin was the first commercial healthcare product derived from rDNA.

2. Human Growth Hormone (hGH)

Human growth hormone (hGH, or somatotropin) is produced in somatotropic cells of the pituitary gland and triggers growth during childhood. Children with growth hormone deficiency exhibit slower physical development and require hormone replacement therapy. Before rDNA, hGH had to be extracted from animal sources, carrying risks of contamination and immune reactions.

A further technical challenge: the human body synthesises a prohormone that must be enzymatically processed to become active. In the 1980s, biotech companies achieved the genetic recombination of the DNA fragment coding for active hGH with suitable plasmids, making the hormone widely available.

rDNA technology is also applied to produce Erythropoietin (EPO) for managing anaemia in patients with kidney failure and cancer, and Tissue Plasminogen Activator (tPA) to dissolve blood clots in stroke patients.

3. Recombinant vaccines

Recombinant subunit vaccines present the immune system with specific molecular parts of pathogens (“subunits”), avoiding exposure to the pathogen itself and offering an excellent safety profile. The DNA fragments coding for the relevant subunit are modified using in vitro techniques such as PCR and reverse transcription, then transferred into easy-to-culture host organisms such as yeast.

The first recombinant subunit vaccine was developed against Hepatitis B in the 1980s; more recently, recombinant subunit technology has been applied to COVID-19 vaccines.

4. Therapeutic antibodies

Recombinant antibodies are among the most sophisticated examples of rDNA technology. Herceptin (Trastuzumab), for instance, is an rDNA-made antibody targeting HER2-positive breast cancer cells. Beyond standard monoclonal antibodies, rDNA enables two advanced antibody formats:

• Bispecific and multispecific antibodies: Molecules engineered to bind two or more distinct epitopes simultaneously. Producing these complex formats requires highly optimised CHO expression platforms to overcome biochemical hurdles like chain mispairing and aggregation.
• Afucosylated and Fc-silenced antibodies: Advanced genetic manipulation of the Fc region either enhances immune system engagement (ADCC) for oncology targets, or silences effector functions entirely to prevent adverse immune reactions.

5. Gene therapies and enzyme production

Gene therapies use rDNA technology to reprogram viruses to insert restorative DNA strands into cells, aiming to restore functionality in cells affected by genetic mutations. Factor VIII, for example, is produced recombinantly to treat patients with Haemophilia A by promoting blood clotting.

Industrial enzyme production is another major example of recombinant DNA technology. Enzymes are used across pharmaceuticals, chemical production, biofuels, and food and beverage manufacturing – a multi-billion-dollar market. rDNA technology allows scientists to manipulate and recombine enzymes from different sources at the genetic level, enhancing their activity, selectivity, and substrate scope, before scaling production via phage-mediated gene introduction into bacteria or yeast.

rDNA and agriculture – examples

Recombinant DNA technology is used to genetically modify plants in order to improve adaptability as well as resistance to harmful agents and to enhance product yield.^​2​

Three widely cited examples of recombinant rDNA technology in agriculture are:

• Bt Crops: Bt crops are genetically modified to express a bacterial gene from Bacillus thuringiensis (Bt), which produces a protein toxic to certain insect pests. These crops, such as Bt cotton and Bt corn, offer built-in insect resistance, reducing the need for chemical insecticides and improving crop yield.
• Golden Rice: Golden Rice is a genetically engineered variety of rice that produces beta-carotene, a precursor of Vitamin A. This biofortified rice aims to combat Vitamin A deficiency in populations relying heavily on rice as a staple food.
• Roundup Ready Crops: Roundup Ready crops, like soybeans and corn, are designed to be resistant to the herbicide glyphosate. This allows farmers to control weeds more effectively, as the crops can withstand glyphosate treatment, reducing the environmental impact of herbicides.

Recombinant DNA technology examples in the food industry

Recombinant DNA technology enables the manufacturing of novel enzymes that are suitable to prolong shelf life and kill foodborne pathogens.​^​2​

Here are 3 examples of recombinant DNA technology in the food industry:

• Chymosin (Rennet): Traditional cheese-making involves using rennet extracted from the stomachs of calves. However, rDNA technology enables the production of chymosin using genetically modified microorganisms like bacteria or yeast. This microbial chymosin is used in cheese production, making the process more efficient and suitable for vegetarians.
• High-Fructose Corn Syrup (HFCS) Production: rDNA technology has been applied to enhance the enzymatic conversion of corn starch into glucose and fructose. This process leads to the production of High-Fructose Corn Syrup, a sweetener used in a wide range of food products.
• Bioengineered Food Additives: Recombinant DNA technology is employed to produce various food additives and enzymes. For instance, certain enzymes used in food processing, such as amylases and proteases, can be manufactured using rDNA methods, ensuring consistent and safe production.

Read more: Application of rDNA technology: What is recombinant DNA used for?

Recombinant production

Recombinant DNA technology describes a process of genetic engineering that uses enzymes and various laboratory techniques to isolate and manipulate genetic material in various steps. This is possible because DNA molecules from all organisms share the same chemical structure, and differ only in the nucleotide sequence. There are different ways to carry out manipulation in an organism’s genome, all with the aim to improve certain characteristics.

Recombinant DNA differs from genetic recombination in that it results from artificial methods in the test tube, while the latter is a normal biological process that results in the remixing of existing DNA sequences in essentially all organisms.

What is needed in recombinant technology?

The DNA sequences used in the construction of recombinant DNA molecules can originate from any eukaryotic species, be it human, bacterial, fungal or mammalian. In addition, DNA sequences that do not occur naturally may be created by chemical synthesis. The different molecular biology tools used in rDNA technology include DNA isolation and analysis, molecular cloning, quantification of gene expression, determination of gene copy number, transformation of the appropriate host for replication starting at a selectable marker, or transfer into crop plants and analyses of transgenic plants.

Respectively, some of the most important instruments needed are enzymes, gene cloning vectors, polymerase chain reaction (PCR) and host organisms. Eligible host organisms for recombinant antibody expression include bacterial and yeast cells, but also insect or mammalian cells, such as HEK293 cells or CHO cells.

What about safety?

When considering the pros and cons of recombinant DNA, safety is a frequently discussed aspect. Generally speaking, recombinant DNA molecules and recombinant proteins are not regarded as dangerous. However, concerns remain about some organisms that express recombinant DNA, particularly when they leave the laboratory and are introduced into the environment or food chain. Such potential safety issues include antibiotic resistance and adverse immune reactions. Outside the health sector concerns include the potential of gene pollution of the environment but also health effects of foods from GMOs.

However, to ensure the greatest degree of safety possible, all rDNA work needs to be compliant with standards and guidelines set out by the FDA and other regulatory institutions.

Apart from safety issues, there is the ethical issue of genetically modified organisms, human genome editing as well as around genetic information in general.

The prospects in recombinant DNA technology

Today, recombinant DNA technology plays a vital role in improving health conditions by developing new vaccines and gene therapy products but also in dealing with several plant disorders, especially viral and fungal resistance.

With the rising prevalence of chronic diseases being one of the main driving factors, the size of the global recombinant DNA technology market is forecast to reach USD 223 billion by 2028, with an annual growth rate of 7.7% during the forecast period.

Bridging Discovery to Pre-Clinical Scale with evitria

To ensure seamless longitudinal comparability, therapeutic developers must generate data natively in CHO cells from day one. As a specialized strategic partner, evitria has focused exclusively on transient CHO expression for over 15 years. Having executed over 140,000 transfections and expressed more than 25,000 distinct antibodies, our platform acts as a seamless extension of internal R&D labs.

By standardizing workflows from rapid HTP antibody production service to gram-scale pre-clinical production with our recombinant antibody production service, we deliver >95% purity and strictly controlled endotoxin levels (<1 EU/mg), ensuring that promising candidates do not fail due to upstream manufacturing variables.