| VLCFA | Very Long Chain Fatty Acids |
|---|---|
| CAA | carotid audiofrequency analysis; cerebral amyloid angiopathy; circulating anodic antigen; Clean Air ... |
| CNBP | cellular nucleic acid binding protein |
| INA | infectious nucleic acid; inferior nasal artery; International Neurological Association |
| NA | Avogadro constant or number; nalidixic acid; Narcotics Anonymous; network administrator; neuraminida... |
| lower GI series | <investigation, radiology> A radiographic diagnostic procedure that involves the introduction of a barium containing contrast material into the lower gastrointestinal tract via the anus. X-rays taken after instillation of the barium will outline the course and anatomy of the lower GI tract. (27 Sep 1997) |
|---|---|
| lymphoid series | The cells at various states in the development in lymphoid tissue of the mature lymphocytes, e.g., lymphoblasts, young lymphocytes, mature lymphocytes. (05 Mar 2000) |
| lyotropic series | <chemistry> A listing of anions and cations in order of their effect on protein solubility (tendency to cause salting out). Essentially a competition between the protein and the ion for water molecules for hydration. (20 Mar 1998) |
| regulatory sequences, nucleic acid | DNA sequences involved in regulating the expression of other genes. (12 Dec 1998) |
| repetitive sequences, nucleic acid | Nucleotide sequences present in multiple copies in the genome. They include direct, inverted, tandem, and terminal repeat sequences and the alu family repeat (named for the restriction endonuclease cleavage enzyme alu I). (12 Dec 1998) |
| minus-strand nucleic acid | <molecular biology> An RNA or DNA strand which has the opposite sense of (would be complementary to) the mRNA of a virus. (12 Jan 1998) |
| sequence homology, nucleic acid | The sequential correspondence of nucleotide triplets in a nucleic acid molecule which permits nucleic acid hybridization. Sequence homology is important in the study of mechanisms of oncogenesis and also as an indication of the evolutionary relatedness of different organisms. The concept includes viral homology. (12 Dec 1998) |
| nucleic acid | <biochemistry, molecular biology> Linear polymers of nucleotides, linked by 3', 5' phosphodiester linkages. In DNA, deoxyribonucleic acid, the sugar group is deoxyribose and the bases of the nucleotides adenine, guanine, thymine and cytosine. RNA, ribonucleic acid, has ribose as the sugar and uracil replaces thymine. DNA functions as a stable repository of genetic information in the form of base sequence. RNA has a similar function in some viruses but more usually serves as an informational intermediate (mRNA), a transporter of amino acids (tRNA), in a structural capacity or, in some newly discovered instances, as an enzyme. The spontaneous loss of the amino groups of cytosine (yielding uracil), methyl cytosine (yielding thymine) or of adenine (yielding hypoxanthine). It can be argued that the presence of thymine in DNA in place of the uracil of RNA stabilises genetic information against this lesion, since repair enzymes would restore the GU base pair to GC. (18 Nov 1997) |
| nucleic acid base | A purine or pyrimidine; found in naturally occurring nucleic acids such as DNA. (05 Mar 2000) |
| nucleic acid conformation | The characteristic 3-dimensional shape of a nucleic acid or polynucleotide. Its secondary structure is due to the formation of hydrogen bonds between nucleotides, resulting in base pairing and areas with alpha helix structure. (12 Dec 1998) |
| nucleic acid denaturation | Disorganization of secondary structures of nucleic acids through cleavage of hydrogen bonds and hydrophobic linkages. Denatured DNA appears to be a single-stranded flexible structure. The effects of denaturation on RNA are similar though less pronounced and largely reversible. (12 Dec 1998) |
| nucleic acid heteroduplexes | Double-stranded nucleic acid molecules (DNA-DNA or DNA-RNA) which contain regions of nucleotide mismatches (non-complementary). In vivo, these heteroduplexes can result from mutation or genetic recombination; in vitro, they are formed by nucleic acid hybridization. Electron microscopic analysis of the resulting heteroduplexes facilitates the mapping of regions of base sequence homology of nucleic acids. (12 Dec 1998) |
| nucleic acid hybridization | Widely used technique which exploits the ability of complementary sequences in single-stranded dnas or rnas to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (kendrew, encyclopedia of molecular biology, 1994, p503; dorlands, 28th ed, p781) (12 Dec 1998) |
| nucleic acid precursors | Use for nucleic acid precursors in general or for which there is no specific heading. (12 Dec 1998) |
| nucleic acid probe | A nucleic acid fragment, labelled by a radioisotope, biotin, etc., that is complementary to a sequence in another nucleic acid (fragment) and that will, by hydrogen binding to the latter, locate or identify it and be detected; a diagnostic technique based on the fact that every species of microbe possesses some unique nucleic acid sequences which differentiate it from all others, and thus can be used as identifying markers or "fingerprints." (05 Mar 2000) |