The present invention provides a filtration chamber comprising a microfabricated filter enclosed in a housing, wherein the surface of said filter and/or the inner surface of said housing are modified by vapor deposition, sublimation, vapor-phase surface reaction, or particle sputtering to produce a uniform coating； and a method for separating cells of a fluid sample, comprising: a) dispensing a fluid sample into the filtration chamber disclosed herein； and b) providing fluid flow of the fluid sample through the filtration chamber, wherein components of the fluid sample flow through or are retained by the filter based on the size, shape, or deformability of the components.本發明係提供一種過濾腔，其包含一容置在殼體中之微加工過濾器，其中該過濾器之表面及/或該殼體之內表面係藉由氣相沉積、昇華、氣相表面反應，或粒子濺射的改質，以產生均勻塗層；以及一種分離流體樣本之細胞的方法，其包含：a）將流體樣本分裝至本文所揭示之過濾腔內；以及b）提供流體樣本之流體流動通過過濾腔，其中流體樣本之成分流動通過或根據成分之大小、形狀，或形變性而留置於過濾器。
