Frequently Asked Questions About rDNA Biotechnology

Q. What is rDNA?

A. Deoxyribonucleic acid (DNA) is the universal code for inheritance of all living things. Recombinant DNA (rDNA) is two pieces of DNA from different organisms that have been joined together into a single piece of DNA. The term recombinant is also used to describe the recombination of DNA from the two parent organisms during sexual reproduction.

Q. What are genes?

A. Genes are short segments of DNA that code for a protein. In essence, they contain the instructions for how to make a certain protein, which is called the gene product. Most genes do not have characteristics specific to the organism in which they are found. In fact, it is impossible to determine the organism from which a gene arises by examining the gene sequence alone; there is no way to identify “fish genes” or “tomato genes.” The uniqueness of the organism lies not only in the DNA sequences of its genes, but also the organization of the genes which are present, and at what time and to what extent they are expressed. Identical genes are regularly found in organisms that are only remotely related.

Q. How is rDNA biotechnology different from conventional breeding?

A. The plants and animals produced by modern agriculture today are the result of more than 10,000 years of genetic modification and refinement. As our scientific understanding of genetics has grown, so has our ability to alter organisms to promote desirable characteristics.

In conventional cross breeding techniques, the DNA of two organisms is randomly combined in the hope that the desired trait will be transferred. However, undesirable traits are also transferred and must be removed through selection in the next several generations. Because the amount of DNA involved is so great and researchers cannot control which genes are transferred into the new organism, this method is far less precise and predictable than rDNA biotechnology methods.

Recombinant DNA technology involves the introduction of one or a few well defined genes. Researchers seeking specific plant characteristics can precisely identify, characterize, enhance, and transfer the appropriate individual genes rather than uncontrolled and randomly assorted groups of genes. The increased precision reduces the chances of unintended effects, and the ability to select genes from virtually any source in nature greatly increases the diversity of useful genes that can be incorporated.

Q. How is it possible for scientists to put DNA from a fish into a strawberry?

A. The random and uncontrolled combination of DNA that takes place during cross breeding is limiting. Trying to cross breed a fish with a strawberry would not yield a viable organism; the genetic makeup of the two organisms is simply too different and the amount of DNA involved is too great. Using rDNA biotechnology, scientists can select a gene in a fish that is responsible for producing a protein that protects the fish from cold temperatures. They can then transfer this single gene into a strawberry plant, which incorporates the gene and produces the new protein. The modification of the genetic makeup of the strawberry is extremely slight—one additional gene joined to tens of thousands of existing genes. Everything about the strawberry is essentially the same, except it now produces a protein that increases its cold resistance.

Q. Are people already eating rDNA biotechnology-derived foods?

A. Probably, unless they eat only 100 percent organic foods. One major trade association has estimated that 70 percent of processed foods contain ingredients derived from corn or soy. Because rDNA biotechnology-derived corn and soy are not stored and handled separately from conventional varieties, most processed foods on the market today contain some ingredients that are at least partially rDNA biotechnology-derived.

Q. Are rDNA biotechnology-derived foods regulated?

A. Yes. The regulation of rDNA biotechnology-derived foods is divided among three major federal agencies: the Food and Drug Administration, the U.S. Department of Agriculture and the Environmental Protection Agency. FDA is responsible for ensuring the safety and proper labeling of foods for human consumption (except for meat and poultry) and for animal feed. It also is responsible for the safety and efficacy of human and animal pharmaceutical products and for human vaccines. USDA’s Food Safety and Inspection Service is responsible for the safety and labeling of meat and poultry products for human consumption. The agency’s Animal and Plant Health Inspection Service regulates the field testing and commercial sale of agricultural rDNA biotechnology-derived crops and is responsible for the safety and efficacy of animal vaccines. EPA is responsible for registering pesticides, setting environmental tolerances for pesticides, and establishing safe levels for pesticide residues in and on crops. Pesticides are substances intended for preventing, destroying, repelling, or mitigating pests.

Q. Do rDNA biotechnology-derived foods violate religious dietary laws?

A. Religious leaders are carefully monitoring and evaluating the developments in rDNA biotechnology. All of the rDNA biotechnology-derived foods on the market to date are considered kosher. In fact, certain applications of rDNA biotechnology have already expanded the use of range of products that would otherwise face religious restrictions. Using rDNA biotechnology-derived chymosin instead of rennet from calves’ stomachs has expanded the range of cheese considered vegetarian, kosher and halal.

Q. Do rDNA biotechnology-derived foods taste the same as conventional foods?

A. Yes. The rDNA biotechnology-derived foods on the market are indistinguishable from conventional foods for taste, color and other sensory characteristics.

Q. Do rDNA biotechnology-derived foods have the same nutrition as conventional foods?

A. The rDNA biotechnology-derived foods currently on the market fall within the normal range for all major nutrients as compared to their conventional counterparts. If they didn’t, the label would disclose the difference. In the not-so-distant future, consumers can expect to see rDNA biotechnology-derived foods that have improved nutritional characteristics such as higher levels of important vitamins. These foods will be appropriately labeled to allow consumers to select these beneficial products.


In an effort to contribute to a meaningful dialogue on scientific issues and consumer concerns about rDNA biotechnology, the Institute of Food Technologists, a non-profit society for food science and technology, conducted a comprehensive review of biotechnology. IFT convened three panels of experts, consisting of IFT members and other prominent biotechnology authorities, to evaluate the scientific evidence and write a report divided into four sections: Introduction, Safety, Labeling, and Benefits and Concerns.