I] 
APPENDIX A 
risk agents. It is not suitable for use with explosive and flammable 
substances, toxic agents, or radioactive materials. 
17. CLASS III BIOLOGICAL SAFETY CABINET: A gas-tight cabinet 
providing total isolation for personnel and product protection with 
a HEPA-filtered air supply and a HEPA -filtered exhaust. The 
cabinet is fitted with gloves and is maintained under negative air 
pressure. This cabinet provides the highest containment reliability 
and should be utilized for all activities involving high-hazard risk 
agents. 
18. CLONE: A population of cells derived, by asexual reproduction, 
from a single cell. Every cell in the population is presumed to 
be genetically identical. In recombinant DNA research, every 
cell in a clone contains the same recombinant DNA species. 
19. CODING SEQUENCE: The orderly array of codons which are 
subunits of a gene. 
20. CHROMOSOME: One or more small rod-shaped body(s) in the 
nucleus of a cell that contains genetic information for that cell. 
A collection of genes. 
21. DEOXYRIBONUCLEIC ACID, or DNA: A complex substance of 
which genes are composed. 
22. EFFLUENT: A liquid or gas flowing from a process. 
23. ENDOGENOUS: Developing or originating within the organism, 
or arising from causes within the organism. 
24. ESCHERICHIA CO LI : A bacterium commonly found in the intestinal 
tract of animals^ 
2 5. ETIOLOGIC AGENT: A viable microorganism or its toxin which 
causes, or may cause, human disease. 
2 6. EUKARYOTIC CELL: A cell that contains a nucleus with a nuclear 
membrane surrounding multiple chromosomes; also contains 
extranuclear organelles. 
27. GENE: The smallest portion of a chromosome that contains the 
hereditary information for the production of a protein. 
28. GENETIC ENGINEERING: Directed intervention with the content 
and/or organization of an organism's genetic complement. 
29. GENOME: The complete set of hereditary information in a cell, 
as the chromosomes in a eukaryote or the single chromosome in 
a prokaryote. 
Appendix A — 3 
