Improvement of specimen preparation technique in atomic force microscope for the bacteriological use.

用AF法对铜绿假单胞菌的丝状噬菌体Pf进行了接触和非接触检测，将纯化后的噬菌体涂抹在干净的盖子上风干。在接触模式下，噬菌体在第一次扫描时就能成像，但在第二次或第三次扫描时，图像很快就消失或错位。在这种模式下，高倍率下的图像质量很好。在非接触模式下，噬菌体细丝可以重复成像，但图像质量不如接触模式。在样品上涂上一层薄薄的等离子体聚合丁烷后，即使是通过接触模式，重复成像也是可能的。在最初的几次成像扫描中，图像质量很高。由于聚合丁烷薄膜太硬，成像针尖很快就会蠕动起来，导致成像质量下降，改善针尖对生物样品的高分辨率成像具有重要意义。

A filamentous bacteriophage pf of Pseudomonas aeruginosa was examined by contact or noncontact mode of AFM.Purified phages were applied on clean cover glass and air dried. By contact mode the phage was able to be imaged by the first scan but the image was soon disappeared or dislocated in 2nd or 3rd scanning. The quality of the image in high magnification was well in this mode. By noncontact mode repeated imaging of the phage filament was capable but the quality of the image was less than that obtained by contact mode. After coating the specimens with a thin layr of plasma polymerized butane, even by the contact mode, repeated imaging became capable. The image quality was high in the initial a few imaging scans. The thin film of polymerized butane was so hard that the tip for imaging was soon worm out and resulted in the deterioration of the imaging quality.Improvement of the tip is important for high resolution imaging in biological specimen.