What are Recombinant DNA (rDNA) Molecules?

Definitions taken from the National Institute of Health (NIH) Guidelines for Research Involving Recombinant DNA Molecules:

  1. Molecules that are constructed outside living cells by joining natural or synthetic DNA segments of DNA molecules that can replicate in a living cell or
  2. Molecules that result from the replication of those described in (1)
  3. Synthetic DNA segments which are likely to yield a potentially harmful polynucleotide or polypeptide (e.g. a toxin or a pharmacologically active agent) are considered as equivalent to their natural DNA counterpart.  If the synthetic DNA segment is not expressed in vivo as a biologically active polynucleotide or polypeptide product, it is exempt from the NIH Guidelines.

Some key questions asked when using rDNA technology are:

  • Where did the gene come from, or what is the “source” (human, animal, etc.)?
  • How will the gene be introduced (i.e. what vector or method of transfection)?
  • What is the target recipient (human, animal, tissue culture, etc.)?

What is an IBC registration document?

It is an application form completed by the principal investigator to describe research activities involving recombinant DNA (rDNA) or infectious agents (see Appendix A of the NIH Guidelines for definitions).

  • Use of rDNA must be registered with and approved by the IBC using the Registration Document for Recombinant DNA. Non-Exempt registrations require full committee review while Exempt registrations are reviewed by an expedited process. Consult Appendix C or D to see definitions of types of recombinant DNA experiments that are classified as Exempt or Non-exempt, respectively.
  • Use of some infectious agents must be registered with and approved by the IBC.  For more information about what constitutes infectious agents, see Appendices A and B. 

What types of agents and materials need to be registered with the IBC?

Faculty and staff who use, possess, store, and or transport infectious agent(s) (e.g. bacteria, viruses, parasites, fungi, protozoa, prions etc.), biological toxin(s), and/or recombinant DNA, must register their use. As listed in the NIH Guidelines:

  • Generation of rDNA constructs
  • Use of rDNA constructs in humans, animals, plants, or tissue culture (including modified cell lines used in animals)
  • Creation of transgenic animals
  • Crossing of two different strains of animals to create a new strain

When and how do I register?


You must register before generating or using any rDNA. Be sure to submit registrations in a timely fashion to allow enough time for a meeting of the IBC to be organized if the registration approval is dependent upon IACUC protocols or grant approvals. Also notify the IBC for implementation of any modifications in your project that requires IBC approval.  


Registration forms can be obtained from the chair of the IBC or on Carleton’s IBC “Register Your Experiment” page. An IBC member will review each registration, inform you of any concerns or modifications needed, and then forward it to the full IBC for final review and approval. Registrations must be renewed every three (3) years.

I receive no funding from NIH. Do I have to register?

Yes. Regardless of funding source, if your research involves infectious agents, biological toxins, Select Agents/Toxins and/or rDNA, you must register with an IBC. Because Carleton receives grant funding from NIH, all research conducted at the College must comply with the NIH Guidelines.

The National Science Foundation (NSF) requires (as stated in Article Subject 38 of the NSF’s “Grant General Conditions” effective January 30, 2017) that NSF grantees who are conducting research that falls within the scope of the NIH Guidelines shall comply with those Guidelines

How do I determine the appropriate Risk Group (RG) for my registration/application?

Risk groups are a classification system for etiological agents; the lower the risk – the lower the risk group class. Biosafety level refers to the physical and procedural barriers used to contain an etiological agent. Risk groups and biosafety containment levels are not proportional determinations. The NIH Guidelines appendices provide definitions regarding risk groups and biosafety levels. If you are unsure of the proper determinations after reviewing this information, please contact the Biosafety Program staff. 

See also Appendix B. Classification of Human Etiologic Agents on the Basis of Hazard.

Risk Group (RG) definitions of biohazardous agents

RG-1 (no or low individual and community risk). A microorganism that is unlikely to cause human disease or animal disease. Agents not associated with disease in healthy adult humans.

RG-2 (moderate individual risk, low community risk). A pathogen that can cause human or animal disease but is unlikely to be a serious hazard to laboratory workers, the community, livestock or the environment. Laboratory exposures may cause serious infection, but effective treatment and preventative measures are available and the risk of spread of infection is limited. Agents associated with human disease that is rarely serious and for which preventive or therapeutic interventions are often available.

RG-3 (high individual risk, low community risk). A pathogen that usually causes serious human or animal disease but does not ordinarily spread from one infected individual to another. Effective treatment and preventive measures are available. Agents associated with serious or lethal human disease for which preventive or therapeutic interventions may be available (high individual risk but low community risk).

RG-4 (high individual and community risk). A pathogen that usually causes serious human or animal disease and that can be readily transmitted from one individual to another, directly or indirectly. Effective treatment and preventive measures are not usually available. Agents likely to cause serious or lethal human disease for which preventive or therapeutic interventions are not usually available (high individual risk and high community risk).

How do I determine the appropriate Biosafety Level (BSL) for my registration/application?

Biosafety level refers to the physical and procedural barriers used to contain an etiological agent. Risk groups and biosafety containment levels are not proportional determinations.

See also Appendix G-II. Physical Containment Levels and Appendix G-III. Footnotes and References of Appendix G

Containment Levels (table credit to CITI training module)

  Biosafety Level 1 Biosafety Level 2 Biosafety
Level 3
Level 4
Practices Basic foundational work practices Level 1 practices plus safe sharps work practices Level 2 work practices, with all work performed inside primary containment devices Same as Level 3
Protective Clothing Gloves and
Lab coat recommended
Gloves and lab coat required; Face protection added if potential for splash or splatter Same as Level 2;
Respiratory protection added if warranted after risk assessment
Supply airline respirator and fully encapsulating protective suit (Suit laboratories)
Containment Equipment None required Biosafety cabinet to contain aerosols; Centrifuge safety buckets and other primary containment equipment Same as Level 2 Same as Level 3; 2nd Configuration of BSL4 is referred to as a Cabinet lab. All work performed in sealed glove boxes
Lab Design Features General lab, easy to clean surfaces, sink, and door Same as Level 1, with recommendation of controlled airflow into the lab and biosafety cabinet for aerosol containment Same as Level 2 with requirement of controlled airflow into the lab, dedicated HVAC system, no recirculation of exhaust, airflow monitoring devices at entry, two-door separation from general traffic, and fan failure alarms Same as Level 3, with many more advanced features; Level 4 is a building within a building approach; All systems for lab separated from non Level 4 areas
Other HEPA filters for exhaust air may be required Double HEPA filtered exhaust air; HEPA filtered supply air; Effluent decontamination system

I am to provide a written risk assessment of my research. What do I need to include?

Overall, an assessment examines the risks associated with the pathogen, procedures, and personnel.

An initial risk assessment should address (the list and checklist below are from the CITI training module “Biohazard Risk Assessment”)

  • Agent and strain (Genus, species, strain designation, and family of microorganisms).
  • Special permits/authorizations required for the agent.
  • Disease caused by the agent.
  • Incubation period (from exposure to onset of symptoms).
  • Signs/symptoms of disease.
  • Route(s) of exposure (inhalation, percutaneous, facial mucous membranes, ingestion).
  • Infectious dose (quantity of organism required for an infection).
  • Pathogenicity (ability to cause disease).
  • Virulence (severity of disease caused, ability to evade host immune system).
  • Environmental stability (survival outside the host in environment, for example, on work surfaces or fabric).
  • Effective disinfectants for inactivation of the pathogen on surfaces, equipment, and in spill situations.
    • Disinfectant (chemical)
    • Concentration
    • Contact time required for decontamination
  • Has the pathogen/agent/biohazard been involved in prior LAIs?
    • If yes, is the route of exposure of LAI known? If it is not known what is the most likely route of exposure?
  • If experiments involve research animals:
    • Is the disease caused in animals?
    • Is transmission from animals to other animals possible?
    • Is transmission from animals to humans possible?
    • Can the animal shed the agent in any of the following secretions?
      • Urine

Risk Assessment Checklist

Agent Characteristics

Agent Name (Biohazard):


Size of Microorganism/Molecule:


Disease(s) Caused:

Signs/Symptoms of Disease:


Risk Group:

Prior Laboratory-Associated Infections:

Route(s) of Exposure:


Host Range:





Gene Product Effects:



Oncogenic Potential:

Physiological Effects:

Infectious Dose:

Incubation Period:



Environmental Stability: Effective Disinfectants:
Procedural Elements
Quantity of Agent (ml/mg): Concentration:
Storage: Transport:
Cell Culture Experiments: Animal Research Experiments:

Cell Lines Utilized:

Type/Size Flasks Utilized:


Animal Species:

Other Diseases Associated with the Animal:

Liquid Transfer Equipment:

Inoculation (route):

Aerosolized System:



Cell Sorting:

Scalpel, Scissors, Fine-tipped forceps:

Board, Pins, Tape:

Sonication: Transport of Samples to Cell Culture Lab:
Other: Other: