Terms Starting with Letter: B backscattering The process of scattering or deflecting into the sensitive volume of a measuring instrument radiations that originally had no motion in that direction. The process is dependent on the nature of the mounting material, the nature of the sample, the type and energy of the radiations, and the particular geometric arrangement. base pair (bp) The subunit of DNA or RNA consisting of adenine, thymine, guanine and cytosine that interact via hydrogen bonds. base sequence The order of nucleotide bases comprising a DNA molecule. beta particle An electron emitted from an unstable nucleus of an atom with an excess of neutrons. Strictly speaking a positron (positive electron) is also a beta particle but commonly beta particle refers to the negatively charged electron form of beta emission. Beta-Galactosidase (Beta-gal) Colorimetric reaction catalyzing enzyme. bilateral Relating to or having two sides. bioinformatics The application of computer and database technology to biological data for the creation of extensive databases in genomics, proteomics (the study of proteins and their interactions), data mining as well as structure prediction. bioluminescence The enzymatic production of visible light by a living organism. Examples include glowworms, fireflies, some bacteria and fungi, and some jellyfish. Bioluminescence imaging is an emerging imaging modality. bioluminescent reporter cells Bioluminescent reporter cells are cells that have been genetically engineered to emit light. Can include light emitting cells that have been introduced to the host or an animal's own cells engineered to emit light. biomarker Any molecule whose presence, absence, or abnormal concentration suggests an abnormal physiologic status associated with injury or disease. See Marker protein. biomimetic Engineered nanomaterial that mimics the behavior of biologic molecules or structures. See Peptidomimetics and Peptide nucleic acid. biophotonic imaging Biophotonics is the science of the interaction of organic matter with light, including the study of light produced by cells, tissues, and organisms (see bioluminescence). Biophotonic imaging is the technology that produces visual and quantitative representations of biophotonic data. In essence, biophotonic imaging makes pictures of biological reactions that produce light. See also in vivo biophotonic imaging. blood curve A collection of data points representing the radioactivity levels in the blood as a function of time. When plotted, these data points form a curve. bombesin Antagonistic peptide for the gastric-releasing peptide (GRP) receptor. Imaging overexpressed GRP receptors can be done utilizing radiolabeled DOTA-bombesin for many cancers. BRCA1/BCRA2 Symbols for the genes breast cancer 1/2 (respectively) that have been associated with familial breast carcinoma. Location: 17q21/13q12.3 (respectively). (source: OMIM)