• Title/Summary/Keyword: Photoncounting

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Quick Detection of Firefly Luciferase Gene Expression in Live Developing Bovine Embryos by Photoncounting

  • Nakamura, A.;Okumura, J.;Muramatsu, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.5
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    • pp.498-502
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    • 1998
  • The present study was designed, fIrst to develop the new methodology to measure the bioluminescence activity easily in live developing bovine embryos by photoncounting, and secondly to compare the expression efficiency of four luciferase reporter genes in bovine embryos at four- to 16-cell stages. In experiment 1, equimolar pSVlacZ and pSVEluc were microinjected into the pronucleus of fertilized bovine oocytes. At 2 days after micro injection, bioluminescence activity of these embryos was measured by photoncounting with a luminometer for 1 min, and lacZ gene expression in the same embryos was assayed by X-gal staining. All the luciferase-positive oocytes showed some bacterial ${\beta}$-galactosidase activity irrespective of the intensity. In experiment 2, four firefly luciferase genes (pTKEluc, pTK6WEluc, pSVEluc and pMiwluc) were introduced by micro injection, and the injected embryos were cultured for the following 2 days. Detection of the luciferase gene expression was done by photoncounting at 5 to 55 min. Over the measurement period, the luciferase activity was almost constant irrespective of the transgenes microinjected. The luciferase activity and expression efficiency at 2 days after microinjection were not significantly affected by the difference in the microinjected transgenes. The present results demonstrated that the bioluminescence activity in live developing bovine embryos could be measured quickly by photoncounting.

Development of lidar detection system for improvement of measurement range (Combined photon counting detection and analog-to-digital signal) (라이다 측정 거리 향상을 위한 통합 수신 시스템 개발 (아날로그방식과 광자계수방식 신호 접합))

  • Shin, Dong Ho;Noh, Young Min;Shin, Sung Kyun;Kim, Young J.
    • Korean Journal of Remote Sensing
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    • v.30 no.2
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    • pp.251-258
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    • 2014
  • We upgraded to utilize a novel method for combining the analog to digital converter and photon-counting measurements for backscatter photon signal of lidar. We have and improve the standard combining method for determination of those conversion factors between analog to digital converter data and photon-counting data measurement which is conducted dead time correction. The combining method and dead time correction method presented here has been successfully applied to experimental data obtained in Gwangju, Korea.