For Transmission Electron Microscopy (TEM), what is the standard pore size of the filters used?

In Transmission Electron Microscopy (TEM), achieving the appropriate sample preparation is crucial for accurate analysis, particularly regarding the filtration process. The standard pore size for filters used in TEM is 0.45 microns. This size is effective for removing larger particles while allowing smaller particles to pass through, ensuring that the collected sample is appropriate for transmission electron microscopy analysis.

Additionally, the mention of an "additional 5.0 microns" typically refers to a measurement that is attributed to the overall effectiveness of the filtration system, rather than being a strict filter requirement. Thus, the focus on the 0.45-micron pore size is essential, as it aligns with TEM protocols which seek to analyze features at the nanoscale without contamination from larger particles that could interfere with imaging and characterization.

Filters with pore sizes that are either larger or significantly different, like those mentioned in the other choices, would not be suitable for the precise requirements of TEM, as they would either allow too many larger particles through or restrict necessary sample components.