Application of enzyme bioluminescence for medical diagnostics

Nowadays luciferases are effectively used as analytical instruments in a great variety of research fields. Of special interest are the studies dealing with elaboration of novel analytical systems for the purposes of medical diagnostics. The ever-expanding spectrum of clinically important analytes accounts for the increasing demand for new techniques for their detection. In this chapter we have made an attempt to summarize the results on applications of luciferases as reporters in binding assays including immunoassay, nucleic acid hybridization assay, and so on. The data over the last 15 years have been analyzed and clearly show that luciferase-based assays, due to extremely high sensitivity, low cost, and the lack of need for skilled personnel, hold much promise for clinical diagnostics.

Ca2+-regulated photoproteins: effective immunoassay reporters

Ca²⁺-regulated photoproteins of luminous marine coelenterates are of interest and a challenge for researchers as a unique bioluminescent system and as a promising analytical instrument for both in vivo and in vitro applications. The proteins are comprehensively studied as to biochemical properties, tertiary structures, bioluminescence mechanism, etc. This knowledge, along with available recombinant proteins serves the basis for development of unique bioluminescent detection systems that are “self-contained”, triggerable, fast, highly sensitive, and non-hazardous. In the paper, we focus on the use of photoproteins as reporters in binding assays based on immunological recognition element—bioluminescent immunoassay and hybridization immunoassay, their advantages and prospects.

Bioluminometric assay for relative quantification of mutant allele burden: application to the oncogenic somatic point mutation JAK2 V617F

Unlike the inherited mutations, which are present in all cells, somatic (acquired) mutations occur only in certain cells of the body and, quite often, are oncogenic. Quantification of mutant allele burden (percentage of the mutant allele) is critical for diagnosis, monitoring of therapy, and detection of minimal residual disease. With point mutations, the challenge is to quantify the mutant allele while discriminating from a large excess of the normal allele that differs in a single base-pair. To this end, we report the first bioluminometric assay for quantification of the allele burden and its application to JAK2 V617F somatic point mutation, which is a recently (2005) discovered molecular marker for myeloproliferative neoplasms. The method is performed in microtiter wells and involves a single PCR, for amplification of both alleles, followed by primer extension reactions with allele-specific primers. The products are captured in microtiter wells and detected by oligo(dT)-conjugated photoprotein aequorin. The photoprotein is measured within seconds by simply adding Ca(2+). We have demonstrated that the percent (%) luminescence signal due to the mutant allele is linearly related to the allele burden. As low as 0.85% of mutant allele can be detected and the linearity extends to 100%. The assay is complete within 50 min after the amplification step.