Hauth Jan, Chodorski Jonas, Wirsen Andreas, Ulber Roland
Fraunhofer ITWM, Kaiserslautern, Germany.
Lehrgebiet Bioverfahrenstechnik, TU Kaiserslautern, Kaiserslautern, Germany.
Biophys J. 2020 May 19;118(10):2354-2365. doi: 10.1016/j.bpj.2020.03.017. Epub 2020 Apr 4.
We expand the standard fluorescence recovery after photobleaching (FRAP) model introduced by Axelrod et al. in 1976. Our goal is to capture some of the following common artifacts observed in the fluorescence measurements obtained with a confocal laser scanning microscope in biofilms: 1) linear drift, 2) exponential decrease (due to bleaching during the measurements), 3) stochastic Gaussian noise, and 4) uncertainty in the exact time point of the onset of fluorescence recovery. To fit the resulting stochastic model to data from FRAP measurements and to estimate all unknown model parameters, we apply a suitably adapted Metropolis-Hastings algorithm. In this way, a more accurate estimation of the diffusion coefficient of the fluorophore is achieved. The method was tested on data obtained from FRAP measurements on a cultivated biofilm.
我们扩展了Axelrod等人在1976年提出的标准光漂白后荧光恢复（FRAP）模型。我们的目标是捕捉在用共聚焦激光扫描显微镜对生物膜进行荧光测量时观察到的一些常见伪影：1）线性漂移，2）指数下降（由于测量过程中的漂白），3）随机高斯噪声，以及4）荧光恢复开始的确切时间点的不确定性。为了将所得的随机模型拟合到FRAP测量的数据并估计所有未知的模型参数，我们应用了一种经过适当调整的Metropolis-Hastings算法。通过这种方式，可以更准确地估计荧光团的扩散系数。该方法在从培养生物膜的FRAP测量获得的数据上进行了测试。
