Principles of Single-Channel Kinetic Analysis

Single-channel recording provides molecular insights that are nearly unattainable from macroscopic measurements. Analysis of the data, however, has proven to be a difficult challenge. Early approach relies on the half-amplitude threshold detection to idealize the data into dwell-times, followed by fitting of the duration histograms to resolve the kinetics. More recent analysis exploits explicit modeling of both the channel and noise statistics to improve the idealization accuracy. The dwell-time fitting has also evolved into direct fitting of the dwell-time sequences using the full maximum likelihood approach while taking account of the effects of missed events. Finally, hidden Markov modeling provides a new paradigm in which both the amplitudes and kinetics can be analyzed simultaneously without the need of idealization. The progress in theory, along with the advance in computing power and the development of user-friendly software, has made single-channel analysis, once a specialty task, now readily accessible to a broader community of scientists.