Phycobiliproteins tandem conjugates

Preparation of a series of phycobiliprotein tandem dyes allows multiplexed analysis of different targets in a sample. In addition, since RPE can be excited by the argon-ion laser at 488 nm, a fluorescein-labeled probe can be used concurrently with RPE alone and RPE-tandem conjugates to create a multiplexed system of different fluorescent probes that can be used simultaneously. Table 9.3 shows the different combinations of dyes that can be used in this type of assay with RPE and APC. 

The use of single laser excitation for multiparameter fluorescence measurements is more challenging. What is needed is a series of fluorophores that all excite at the same laser wavelength, typically the 488 nm argon ion laser line, but which emit at different distinguishable wavelengths. One series of such labels includes fluorescein, R-PE, and either Cy5-labeled R-PE or Texas Red-labeled R-PE tandem conjugates or another phycobiliprotein, PerCP. Fluorescein emits at 525 nm, R-PE at 575 nm, and Cy5-PE at 670 nm, and each can be detected with minimum spillover from the others. ... 

Glazer, A.N., and Stryer, L. (1983) Fluorescent tandem phycobiliprotein conjugates Emission wavelength shifting by energy transfer. Biophys. /. 43, 383-386. 

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