| 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) |
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| DNA probe | <molecular biology> A small piece of nucleic acid that has been labelled with a radioactive isotope, dye, or enzyme and is used to locate a complementary nucleotide sequence or gene on a DNA molecule. (14 Nov 1997) |
| electron probe | <physics> A narrow beam of electrons used to scan or illuminate an object or screen. (05 Aug 1998) |
| electron probe microanalyser | <apparatus> The qualitative and quantitative use of X-rays excited by a microprobe of electrons. Available with scanning electron microscope and transmission electron microscope. Acronym: EMA (05 Aug 1998) |
| electron probe microanalysis | Identification and measurement of concentration of elements based on the fact that primary-emission X-rays emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It may be performed by an electron probe microanalyzer, an electron microscope microanalyzer, or by an electron microscope, or scanning electron microscope, fitted with an X-ray spectrometer. (12 Dec 1998) |