Microbial DNA diagnostic technology

Non-radioactive analysis of biomolecules

An overview on non-radioactive bioanalytical indicator systems is presented. The nature of labels being important for direct as well as indirect systems is discussed. This is followed by the description of enzymatic, photochemical and chemical methods for labeling nucleic acids, proteins and glycans. These methods can be applied either for direct labeling of these biomolecules or for labeling of respective probes (DNA, RNA, oligonucleotides, antibodies, lectins). In the second part, various optical, luminescent and fluorescent detection approaches are described. The possibility to enhance the sensitivity by coupled amplification reactions (signal amplification, target-specific signal amplification, target amplification) is shown in a separate section. Finally, the wide variety of qualitative and quantitative reaction formats related to different applications is collected.

The digoxigenin:anti-digoxigenin (DIG) technology--a survey on the concept and realization of a novel bioanalytical indicator system

A review is given on the novel non-radioactive digoxigenin:anti-digoxigenin (DIG) bioanalytical indicator system. After a general introduction on direct and indirect indicator systems based on previous non-radioactive indicator reactions as well as in vitro and in vivo amplification procedures the principle of the new digoxigenin:anti-digoxigenin technology is demonstrated. The novel system is based on the specific high-affinity interaction between the cardenolide digoxigenin from Digitalis plants and a digoxigenin-specific antibody coupled with a reporter group. A variety of methods for digoxigenin modification of nucleic acids, proteins and glycans are presented. In addition, various applications of the novel non-radioactive indicator system in a variety of direct or indirect detection approaches with either insoluble or soluble substrates are described. It is also shown that with these applications alternative reaction formats are used which are partly characterized by additional amplification steps.