biostudies-literatureUnknown5(1)Zhu DRelative to the 300-kV accelerating field, electrons accelerated under lower voltages are potentially scattered more strongly. Lowering the accelerate voltage has been suggested to enhance the signal-to-noise ratio (SNR) of cryo-electron microscopy (cryo-EM) images of small-molecular-weight proteins (<100 kD). However, the detection efficient of current Direct Detection Devices (DDDs) and temporal coherence of cryo-EM decrease at lower voltage, leading to loss of SNR. Here, we present an electron counting algorithm to improve the detection of low-energy electrons. The counting algorithm increased the SNR of 120-kV and 200-kV cryo-EM image from a Falcon III camera by 8%, 20% at half the Nyquist frequency and 21%, 80% at Nyquist frequency, respectively, resulting in a considerable improvemenCommunications biology321https://www.ebi.ac.uk/biostudies/studies/S-EPMC8987035biostudies-literatureAn electron counting algorithm improves imaging of proteins with low-acceleration-voltage cryo-electron microscope.PMC8987035Zhang XWu CZhu DShi HfalseAn electron counting algorithm improves imaging of proteins with low-acceleration-voltage cryo-electron microscope.Relative to the 300-kV accelerating field, electrons accelerated under lower voltages are potentially scattered more strongly. Lowering the accelerate voltage has been suggested to enhance the signal-to-noise ratio (SNR) of cryo-electron microscopy (cryo-EM) images of small-molecular-weight proteins (<100 kD). However, the detection efficient of current Direct Detection Devices (DDDs) and temporal coherence of cryo-EM decrease at lower voltage, leading to loss of SNR. Here, we present an electron counting algorithm to improve the detection of low-energy electrons. The counting algorithm increased the SNR of 120-kV and 200-kV cryo-EM image from a Falcon III camera by 8%, 20% at half the Nyquist frequency and 21%, 80% at Nyquist frequency, respectively, resulting in a considerable improvemen2022-01-01T00:00:00Z2022 Apr2025-04-21T16:50:57.665Z2025-04-21T16:50:57.665ZS-EPMC89870353538817410.1038/s42003-022-03284-1