Quantifoil圆孔碳支持膜更适合于低温透射电子显微镜（TEM），因为圆形孔眼更有助于形成均匀厚度的冰层。孔间距的选择取决于所需放大倍数和是否将支撑膜印迹置入最终影像中。如果膜片被置入最终影像，那么影像质量评定就比较容易，因为膜片在功率谱上要比孤立的冰层大许多。孔径2和1.2µm的Quantifoil圆孔膜片可用于30,000至40,000倍放大。如果需要较大的射束位置公差或射束直径（如在自动影像采集中），推荐使用Quantifoil R2/4。当在一个深印于冰中的小孔边缘聚焦，而非在临近小孔的薄膜上聚焦时，通常适用于R 2/1。 碳膜的厚度被严格控制在10-12 nm的范围

QUANTIFOIL® with circular holes

QUANTIFOIL® with circular holes is mainly used in cryo-EM. The roundness of the holes is advantageous with respect to the formation of an ice layer of constant thickness.

The hole size that is chosen depends on the magnification used, and on whether or not one wishes to include support film in the image. The latter makes assessment of the image quality easier, because the power spectrum of a foil is stronger than that of unsupported ice.

R 1/4 R 2/1 R 3.5/1

The QUANTIFOIL® types with small holes (e.g. 1.2 µm) were designed for magnifications around and higher 50.000x. At magnifications between 30.000x and 40.000x we recommend the QUANTIFOIL® types with 2 µm holes. Larger holes (e.g. 3.5 µm, 5 µm) are suitable at magnification around 20.000x.

The table below gives an overview of the available QUANTIFOIL® types with circular holes. Please be aware that the hole size and spacing might vary slightly from their nominal value, whereas the period is fix.