水环境微生物样品取样方法
海水宏基因组样品的采集方法:
参照文献:Jorge Frias-Lopez, Yanmei Shi, et al.(2008). Microbial community gene expression in ocean surface waters.PNAS, 105(10): 3805-3810.
1) 用125mm孔径的GF/A滤器将海水预过滤 (Whatman, Maidstone, U.K.),然后采用孔径为0.22um的Steripak-GP20滤器(Millipore, Bedford, MA)、Masterflex peristaltic 泵(Cole Parmer Instrument Company, Vernon Hills, IL)抽滤
2) 待260L水样抽滤完毕,用裂解液(50 mM Tris•HCl, 40 mM EDTA, 0.75 M 蔗糖)覆盖Steripak-GP20滤器,并置于-80℃冻存待用
海水样品DNA提取方法:
M.T. Suzuki1, C.M. Preston, et al.(2004). Phylogenetic Screening of Ribosomal RNA Gene-Containing Clones in Bacterial Artificial
Chromosome (BAC) Libraries from Different Depths in Monterey Bay. Microbial Ecology; 48: 473-488.
1) 于Monterey海湾的M1 (36o45.50N 122o02.10W)位点的100m深度处收集1400L海水,用GFA滤器(Millipore, Billerica, MA)过滤,然后采用切向流(Tangential flow filtration)DC-10L系统,使用中空纤维滤芯(30,000-Da cutoff, H10P30-20, Millipore))离心浓缩至330mL的终体积
2) 加入8L回洗液洗涤中空纤维滤芯,并浓缩到500mL
3) 将浓缩液再次用Pellicon XL50系统,采用30-kDa NMWL滤芯 (Pellicon 2 Maxi Filter, Millipore) 离心浓缩到15mL的终体积;接着再离心(12,000×g, Brinkmann 5415D, Westbury, NY),沉淀-80℃留存待用
4) 沉淀用含有浓度为0.5 mg mL–1的蛋白酶K(Fisher, Fairlawn, NJ))和1%的
SDS(Sigma, St Louis, MO) 的蔗糖裂解液(40 mM EDTA, 50 mM Tris HCl, pH 8.0, 0.75 M sucrose)重悬,于55℃温浴20min
5) 将细胞裂解液于70℃温浴5min,然后用酚氯仿异戊醇(酚:氯仿:异戊醇=24:24:1,Sigma)抽提2次,氯仿异戊醇(氯仿:异戊醇=24:1,Sigma)抽提1次
6) 收集水相,用Centricon 100 (Millipore)超滤(见商品操作指南)
7) 通过CsCl浮力平衡离心(Buoyant equilibrium centrifugation,详见:Suzuki, MT, Taylor, LT, DeLong, EF. (2000). Quantitative analysis of small-subunit rRNA genes in mixed microbial populations via 5,-nuclease assays. Appl Environ Microbiol 66(11): 4605–4614),获得纯化的DNA
水环境微生物样品取样方法
海水宏基因组样品的采集方法:
参照文献:Jorge Frias-Lopez, Yanmei Shi, et al.(2008). Microbial community gene expression in ocean surface waters.PNAS, 105(10): 3805-3810.
1) 用125mm孔径的GF/A滤器将海水预过滤 (Whatman, Maidstone, U.K.),然后采用孔径为0.22um的Steripak-GP20滤器(Millipore, Bedford, MA)、Masterflex peristaltic 泵(Cole Parmer Instrument Company, Vernon Hills, IL)抽滤
2) 待260L水样抽滤完毕,用裂解液(50 mM Tris•HCl, 40 mM EDTA, 0.75 M 蔗糖)覆盖Steripak-GP20滤器,并置于-80℃冻存待用
海水样品DNA提取方法:
M.T. Suzuki1, C.M. Preston, et al.(2004). Phylogenetic Screening of Ribosomal RNA Gene-Containing Clones in Bacterial Artificial
Chromosome (BAC) Libraries from Different Depths in Monterey Bay. Microbial Ecology; 48: 473-488.
1) 于Monterey海湾的M1 (36o45.50N 122o02.10W)位点的100m深度处收集1400L海水,用GFA滤器(Millipore, Billerica, MA)过滤,然后采用切向流(Tangential flow filtration)DC-10L系统,使用中空纤维滤芯(30,000-Da cutoff, H10P30-20, Millipore))离心浓缩至330mL的终体积
2) 加入8L回洗液洗涤中空纤维滤芯,并浓缩到500mL
3) 将浓缩液再次用Pellicon XL50系统,采用30-kDa NMWL滤芯 (Pellicon 2 Maxi Filter, Millipore) 离心浓缩到15mL的终体积;接着再离心(12,000×g, Brinkmann 5415D, Westbury, NY),沉淀-80℃留存待用
4) 沉淀用含有浓度为0.5 mg mL–1的蛋白酶K(Fisher, Fairlawn, NJ))和1%的
SDS(Sigma, St Louis, MO) 的蔗糖裂解液(40 mM EDTA, 50 mM Tris HCl, pH 8.0, 0.75 M sucrose)重悬,于55℃温浴20min
5) 将细胞裂解液于70℃温浴5min,然后用酚氯仿异戊醇(酚:氯仿:异戊醇=24:24:1,Sigma)抽提2次,氯仿异戊醇(氯仿:异戊醇=24:1,Sigma)抽提1次
6) 收集水相,用Centricon 100 (Millipore)超滤(见商品操作指南)
7) 通过CsCl浮力平衡离心(Buoyant equilibrium centrifugation,详见:Suzuki, MT, Taylor, LT, DeLong, EF. (2000). Quantitative analysis of small-subunit rRNA genes in mixed microbial populations via 5,-nuclease assays. Appl Environ Microbiol 66(11): 4605–4614),获得纯化的DNA