Homogenous time-resolved fluorescence assay

Cencic, R., Yan, Y., and Pelletier, J. (2007). Homogenous time resolved fluorescence assay to identify modulators of cap-dependent translation initiation. Comb. Chem. High Throughput Screen 10, 181-188. 

Ferrer, M. et al. 2003 Miniaturizable homogeneous time-resolved fluorescence assay for carboxypeptidase B activity. Anal. Biochem. 317. 94-98. 

Homogeneous Time Resolved Fluorescence (HTRF) (Cisbio International) is an assay based on the proximity of a lanthanide cryptate donor and a fluorescent acceptor molecule whose excitation wavelength overlaps that of the cryptate s emission. The utility of this technique is based on the time resolved fluorescence properties of lanthanides. Lanthanides are unique in the increased lifetime of their fluorescence decay relative to other atoms, so a delay in collection of the emission intensity removes the background from other fluorescent molecules. An example of the HTRF assay is a generic protein-protein interaction assay shown in Fig. 2. 

Liang, A.M., Claret, E., Ouled-Diaf, J., Jean, A., Vogel, D., Light, D.R., Jones, S.W., Guilford, W.J., Parkinson, J.F., and Snider, R.M. (2007) Development of a homogeneous time-resolved fluorescence leukotriene B4 assay for determining the activity of Leukotriene A4 hydrolase. J. Biomol. Screen. 12, 536-545. 

Karvinen, J. et al. 2002. Homogeneous time-resolved fluorescence quenching assay (LANCE) for caspase 3. J. Biomol. Screen. 1, 223-231. 

Primary Homogeneous Time-Resolved Fluorescence (HTRF) HTS Assay.84... 

PRIMARY HOMOGENEOUS TIME-RESOLVED FLUORESCENCE (HTRF) HTS ASSAY... 

Inherent fluorescence in natural product samples rules out the use of frank fluorescence as an assay readout. In the early 1990s, the development of homogeneous time-resolved fluorescence (HTRF) allowed the use of fluorescence with such samples (Kolb, Yamanaka, and Manly, 1996 Kolb and Manly, 1997 Bazin, Trinquet, and Mathis, 2002 Mathis, 1999). This technique... 

The homogeneous TRF assay formats HTRF ( homogeneous time-resolved fluorescence ) by GisBio International [115, 120, 136, 137] and LANGE ( lantha-... 

HTRF/LANCE - homogeneous time-resolved fluorescence/lanthanide cryptate excitation SPA - scintillation proximity assay - homogeneous assay which detects radioisotopes in close proximity to a solid scintillant ... 

A study at Novartis compared hits obtained by screening 30,000 compounds for tyrosine kinase activity in three different assays a scintillation proximity assay (SPA), a homogeneous time-resolved fluorescence energy transfer assay (HT-FRET), and a fluorescence polarization (FP) assay.Library compounds were screened as mixtures of five in a well, which meant that after active wells were identified, the five constituents would be deconvoluted by screening each compound individually or using other methods to establish which of the compounds was active. " When this was done SPA, HT-FRET, and FP turned up 30, 59, and 64 hits respectively. A low degree of overlap was observed between the sets. Only four or seven compounds, depending on where the activity bars were set, would have been identified... 

The structures of fluorescent lanthanide chelates used for separation and homogeneous time resolved fluorometric assays. 

An example of a recent development in assay technology that combines speed, sensitivity and safety is homogeneous time resolved fluorescence (HTRF , Packard). HTRF has the inherent sensitivity associated with fluorescence, but is designed to eliminate or compensate for problems such as high background, color interference and fluorescence quenching often found in biological assays. 

Product and services of interest include genomics, proteomics, custom research and services, and instruments, accessories, consumables and software. PerkinElmer proprietary technologies include time-resolved fluorescence which is employed in the sensitive Wallac DELFIA system and Wallac LANCE homogeneous assay system, and fluorescence polarization, [FP]2 , a robust fluorescence-based technique for receptor binding assays that is both fast and easy-to-use. 

In the past ten years, numerous applications of fluorescence methods for monitoring homogeneous and heterogeneous immunoassays have been reported. Advances in the design of fluorescent labels have prompted the development of various fluorescent immunoassay schemes such as the substrate-labeled fluorescent immunoassay and the fluorescence excitation transfer immunoassay. As sophisticated fluorescence instrumentation for lifetime measurement became available, the phase-resolved and time-resolved fluorescent immunoassays have also developed. With the current emphasis on satellite and physician s office testing, future innovations in fluorescence immunoassay development will be expected to center on the simplification of assay protocol and the development of solid-state miniaturized fluorescence readers for on-site testing. 

Laitala V, Hemmila L. Homogeneous assay based on low quan- 83. turn yield Sm(lll)-donor and anti-Stokes shift time-resolved fluorescence resonance energy-transfer measurement. Analyt. Chim. 

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