DNA, probe

A method being developed increasingly is the use of DNA probes. These use radiolabelled single stranded DNA (the probe), which attaches to complementary DNA to form double stranded DNA hybrids. The test is carried out on a solid phase such as a cellulose nitrate filter. The double stranded DNA remains bound to the filter, whilst the single stranded material is washed off. The radioactivity taken up into the double strand may then be assessed. The method is rapid and has great potential, although the main drawback will probably be the disposal of the radioactive material. 

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L. J. Kricka, ed., Nonisotopic DNA Probe Techniques, Academic Press, Inc., San Diego, Calif., 1992. 

Biosensors (qv) and DNA probes ate relatively new to the field of diagnostic reagents. Additionally, a neat-infrared (nit) monitoring method (see Infrared TECHNOLOGY AND RAMAN SPECTROSCOPY), a teagenfless, noninvasive system, is under investigation. However, prospects for a nit detection method for glucose and other analytes ate uncertain. 

Screen-printed gold electrodes were, firstly, modified with a mixed monolayer of a 25-mer thiol-tethered DNA probe and a spacer thiol, 6-mercapto-1 -hexanol (MCH). The DNA probe sequence was internal to the sequence of the 35S promoter, which sequence is inserted in the genome of GMOs regulating tire transgene expression. 

A diagnostic method using fluorescence labeled DNA probes to detect and quantify the number complementary chromosomal sequences on a cellular resolution. A related technique that also allows assessment of gene amplifications, but without precise quantification of copy numbers is the chromogenic in situ hybridization (CISH). Here, instead of a fluorescent dye an enzyme that can generate a colored precipitate in the tissue samples is coupled to the DNA probe. 

Belotserkovskii B.P., Zarling D.A. Peptide nucleic acid (PNA) facilitates multistranded hybrid formation between linear double-stranded DNA targets and RecA protein-coated complementary single-stranded DNA probes. Biochemistry 2002 41 3686-3692. 

The ultimate goal of microarray-based expression analysis is to acquire a comprehension of the entire cellular process, in order to exploit and to standardize the multidi-menisional relations between genotype and phenotype. However, an increasingly important parameter, which has not yet been substantially taken into account, is the role of cellular translation. This means that mRNA expression data need to be correlated with the assortment of proteins actually present in the cell. One approach is based on the use of microarrays containing double-stranded DNA probes for the analysis of DNA-protein interaction and, thus, the detection and identification of DNA-binding proteins by means of fluorescence [130] or mass spectrometry analysis [131]. Moreover, substantial efforts are currently under way to develop protein, antibody, or even cell arrays, applicable to the cor-... 

Certain mutant hemoglobins are common in many populations, and a patient may inherit more than one type. Hemoglobin disorders thus present a complex pattern of clinical phenotypes. The use of DNA probes for their diagnosis is considered in Chapter 40. 

Southwestern hlot A method for detecting pro-tein-DNA interactions by applying a labeled DNA probe to a transfer membrane that contains a rena-tured protein. 

Bifunctional adamantyl, as a hydrophobic central core, can be used to construct peptidic scaffolding [151], as shown in Fig. 27. This is the reason why adamantane is considered one of the best MBBs. This may be considered an effective and practical strategy to substitute different amino acids or DNA segments on the adamantane core (Fig. 28). In other words, one may exploit nucleic acid (DNA or RNA) sequences as linkers and DNA hybridization (DNA probe) to attach to these modules with an adamantane core. Thus a DNA-adamantane-amino acid nanostructure may be produced. 

FISH. Fluorescent in-situ hybridization a method utilizing fluorescently labeled DNA probes to detect or confirm gene or chromosome abnormalities that are generally beyond the resolution of routine cytogenetics. 

Electrogenerated chemiluminescence (ECL) has proved to be useful for analytical applications including organic analysis, ECL-based immunosensors, DNA probe assays, and enzymatic biosensors. In the last few years, the electrochemistry and ECL of compound semiconductor nanocrystallites have attracted much attention due to their potential applications in analytical chemistry (ECL sensors). 

A non-radioactively labeled DNA probe of 742bp was used for the hybridization. The probe was obtained from a genomic DNA fi om FORL r2 using the same oligonucleotide above mentioned and the same conditions. The... 

There is an indeterminacy in the term oligotroph, and the dilemma is exacerbated by the fact that it may be impossible to isolate obligate oligotrophs by established procedures. The application of DNA probes should, however, contribute to an understanding of the role of these noncultivable organisms. Oligotrophic bacteria in the marine environment are able to utilize low substrate concentrations, and they may be important in pristine environments. 

Diels L, M Mergeay (1990) DNA probe-mediated detection of resistant bacteria from soils highly polluted by heavy metals. Appl Environ Microbiol 56 1485-1491. 

Holben WE, JK Jansson, BK Chelm, JM Tiedje (1988) DNA probe method for the detection of specific microorganisms in the soil bacterial community. Appl Environ Microbiol 54 703-711. 

Samadapour M, J Liston, JE Ongerth, PI Tarr (1990) Evalnation of DNA probes for detection of Shiga-like-toxin-producing Escherichia coli in food and calf fecal samples. Appl Environ Microbiol 56 1212-1215. 

D. Redecker, T. Batinic, I. S. Feder, K. Koseh, U. Schulz, P. Vinuesa, and D. Werner, Biocontrol strain Pseudomomis fluorescens W34 specific detection and quantification in the rhizo.sphere of Cucumis salivus with a DNA probe and characterization by DNA fingerprinting. 2. Natmforsch. 54c 359 (1999). 

Nucleic acid hybridization methods use oligonucleotide DNA probes with sequences complementary to a portion of the nucleic acid of the target bacterium38,60 and designed to hybridize with immobilized DNA or RNA on a membrane. After any unbound probe has been washed off, the hybridized probe can be detected.64 66... 

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