求帮忙翻译（生物学）

Construction of swine macrophage cDNA libraries. cDNA libraries were generated from mRNA isolated from ASFV-infected and uninfected macrophage cell cultures (60 75-cm2 flasks) prepared from swine peripheral blood mononuclear cells (19). Macrophages were infected with pathogenic ASFV isolate Pr4 at a high multiplicity of infection (MOI) of 20, and at 3, 6, and 18 h postinfection (hpi), infected cells were harvested and lysed. RNA was extracted with acid phenol-chloroform and precipitated with isopropanol. Total RNA was purified by LiCl precipitation, and poly(A) RNA transcripts were enriched by two successive rounds of oligo(dT) affinity chromatography (28). Five micrograms of mRNA was used to generate directional cDNA libraries with commercially available cDNA synthesis and cloning kits (Superscript II system; Life Technologies). Approximately 15,000 cDNA clones were sequenced and characterized by comparison to genetic databases (J. Neilan, unpublished data). Seven thousand seven hundred twelve cDNA clones from two cDNA libraries (2,925 from an ASFV-infected macrophage library and 4,787 from a noninfected macrophage library) were selected by Blast analysis with a cutoff value of 200 (2) and used to construct a cDNA microarray.