本研究中利用原子力顯微鏡(atomic force microscopy, AFM)在細菌近生理狀態下(near-physiological environment)觀察大腸桿菌(Escherichia coli, E. coli) 和線狀噬菌體M13 (filamentous bacteriophage, phage)之交互作用。利用原子力顯微鏡之力曲線(force-distance curve, f-d curve)可以藉由虎克定律(Hooke’s law)以及赫茲模型(Hertz model)，去計算出細菌在感染前後之有效彈簧常數 (effective spring constant)以及楊氏係數(Young’s modulus)的變化，發現當細菌被噬菌體感染後有效彈簧常數以及楊氏係數，兩者都有些微的下降。同時利用原子力顯微鏡優異的成像能力，比較在水中大腸桿菌被噬菌體M13感染前感染後的形貌以及粗糙度。比較兩者數據後發現大腸桿菌在被感染後表面變得比較平坦，少了一些凸起物，推測原因是由於細菌表面在被噬菌體感染後，遭受了一些破壞。
過去研究中提到，當細菌被噬菌體感染後，表面的脂多醣(lipopolysacchride, LPS)會被破壞、釋放。為了證明大腸桿菌被噬菌體感染後表面的LPS會被破壞、釋放，我們使用乙二胺四乙酸二鈉 (ethylenediaminetetraacetates, EDTA)對大腸桿菌做處理，EDTA為二價離子螯合劑，EDTA使得細菌將表面的LPS釋放，將被處理過的大腸桿菌和被感染過的大腸桿菌相比較，可發現不僅在機械性質方面雷同，大腸桿菌膜表面同樣呈現平坦與光滑，因此推斷此一變化的確可能肇因於表面LPS的破壞。除此之外，本研究也利用原子力顯微鏡探針輕壓大腸桿菌並定住，以量取研究當細菌被噬菌體感染後是否會對此壓力有一些不同的現象產生。本研究主要是希望利用原子力顯微鏡探討當細菌被噬菌體感染後之機械性質變化，並希望藉由此一研究能夠發揮原子力顯微鏡在生物研究之優勢，且利用其允許生物在近生理環境下具高解析與可對表面機械性質分析來觀察到其他儀器所不能觀察到的現象。

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