During the offline analysis (offline shorter), some of the channels shows signals (waveform) which aggregates at the center of the PC1, PC2/PC3 axis in a 2D/3D cluster view. However, the same cluster was shifted away from the center when the other features like peak height, valley height, peak-valley difference were applied. During unit recording (Plexon, Multichannel acquisition processor) the threshold slider was set below 20 from the center line. What are the possible ways to distinguish between a cluster of units (signal) and noise in a single unit recording. I am using array of single electrodes to record units from dorsal hippocampus, in freely behaving rats. Thanks