PCR法检测转基因大豆毛状根的hbFGF基因

目的通过检测转基因大豆毛状根的人碱性成纤维细胞生长因子(hbFGF),为利用毛状根生产药物实现工业化提供实验基础。方法采用PCR检测方法,利用植物基因组DNA提取试剂盒,兔抗人bFGF单克隆抗体进行对转基因大豆毛状根hbFGF检测。结果用PCR检测转基因大豆毛根,并在60条Hyg抗性大豆毛状根中鉴定出19条大豆毛状根整合状hbFGF,阳性率为32%。兔抗人bFGF单克隆抗体检测表明,hbFGF在转基因大豆毛状根中稳定表达。结论转基因大豆毛状根能够稳定表达hbFGF基因,在工业生产中具有广阔的前景。     

抗重组人bFGF单克隆抗体可变区基因克隆及单链抗体的构建和表达

目的：从分泌抗重组人碱性成纤维细胞生长因子（bFGF）单克隆抗体（mAb）杂交瘤细胞株B2F3中克隆抗体可变区（V）基因，构建bFGF单链抗体（scFv），并进行可溶性表达。方法：从分泌bFGF mAb杂交瘤细胞株B2F3提取总RNA，用RT-PCR方法扩增抗体重链可变区基因（VH）和轻链的可变区基因（VL）；再通过重叠延伸拼接（SOE）PCR方法，在VH和VL基因之间引入linker（Gly4Ser）3，构建bFGF scFv。将测序正确的scFv基因克隆到表达载体pCANTAB 5E中，选择非抑制型菌株E.coli HB2151进行可溶性表达；经SDS—PAGE检测抗体表达水平，ELISA鉴定其抗原结合活性。结果：测序分析结果显示，VH基因序列全长375碱基对，编码125个氨基酸，VL基因序列全长399碱基对，编码133个氨基酸，二者均符合小鼠免疫球蛋白可变区基因特征，含有4个框架区（FR）、3个抗原互补决定区（CDR）及抗体特征性的2个半胱氨酸残基；构建的scFv全长789碱基对，编码263个氨基酸，连接结构为VH-linker-VL。SDS-PAGE分析表明scFv基因在大肠杆菌为可溶性表达，表达产物主要位于周质腔中，表达产物的Mr为27000，与理论预期值相符；间接ELISA检测结果显示原核表达的scFv具有与bFGF特异性结合的活性。结论：成功地克隆bFGF mAb可变区基因，并构建表达bFGF scFv，为下一步研究bFGF抗体人源化改造奠定实验基础。     

碱性成纤维细胞生长因子-慢病毒真核表达载体的构建及转染

背景：以往研究多采用质粒载体,由于其转染效率不高,且转染时需借助脂质体转染剂进行转染,转染具有细胞毒性,操作复杂等难以应用于临床。 目的：构建携带人碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)基因的慢病毒载体,转染成骨方向诱导的骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs),鉴定bFGF基因表达。 方法：实验组：设计人bFGF基因引物,用Trizol法提取胎盘组织RNA,用RT-PCR的方法扩增出bFGF基因,连接至pLenti6/V5-D-TOPO® 表达质粒,经Xho-Ⅰ、BamH-Ⅰ双酶切和DNA测序证实质粒正确构建。在脂质体转染剂Lipofectamine 2000的介导下,将bFGF-pLenti6/V5-D-TOPO表达质粒同包装质粒pLP1、pLP2、 包膜质粒pLP/VSVG 共转染293FT细胞株,收集bFGF-慢病毒上清转染诱导后第2代的兔BMSCs。对照组：设计GFP基因引物,以GFP- PMSLV-Plazmid为模板,PCR的方法扩增出GFP基因,连接至pLenti6/V5-D-TOPO® 表达质粒,构建GFP-慢病毒载体,并转染BMSCs。RT-PCR和Wetern-blot方法检测bFGF、GFP基因的表达。 结果与结论：转染48 h后,对照组BMSCs可见绿色荧光蛋白表达;实验组BMSCs在转染15 d后,RT-PCR方法扩增出bFGF基因,Western-blot检测出目的蛋白表达。提示成功构建携带人bFGF和GFP基因的真核表达载体,建立转染兔BMSCs的方法。     

抗人红细胞H抗原单链抗体基因克隆和表达

目的 克隆抗人红细胞H抗原单克隆抗体轻、重链可变区(VH、VL)基因并构建单链抗体(ScFv)基因及其表达载体,实现其在原核细胞中的表达.方法 从分泌抗人红细胞H抗原单克隆抗体的杂交瘤细胞株2FA中提取总RNA,采用RT-PCR法获得抗人红细胞H抗原单克隆抗体的VH、VL基因;利用重叠引物延伸法(splicing by overlap extension,SOE)将轻重链可变区基因连接,并引入连接肽(Linker)编码序列,构建VH-Linker-VL结构的单链抗体(ScFv)基因,将其克隆到原核表达载体pET-his中,转化BL21(DE3)plysS细胞,IPTG诱导表达;获得的目的蛋白经纯化后,用SDS-PAGE与Westem blotting对目的蛋白进行鉴定,间接EHISA、竞争ELISA和免疫荧光法检测目的蛋白的活性.结果 克隆的VH基因长度为351 bp,属于鼠抗体可变区重链基因家族I(B)亚群;VL基因长度为339 bp,属于鼠抗体可变区轻链基因家族I亚群;SOE法克隆的单链抗体基因为750 bp;构建的含原核表达载体的菌株经IPTG诱导后,SDS-PAGE及Western blotting法检测到Mr 32 000的目的蛋白(表达的ScFv);ScFv纯化后,经免疫荧光法、间接与竞争HLISA法检测到该ScFv蛋白具有生物结合活性.结论 成功地克隆了抗人红细胞H抗原单克隆抗体VH与VL基因和ScFv基因,构建ScFv基因的表达载体,实现了ScFv在大肠杆菌BL21(DE3)plysS细胞中的活性表达,为基于红细胞H抗原的免疫检测技术建立奠定了基础.     

人连接蛋白Connexin26基因的克隆、表达及初步鉴定

目的研究含人连接蛋白Connexin26（Cx26）基因的真核表达载体构建及其在非洲猴肾细胞（COS-7）中获得稳定、高效表达的方法。方法提取人外周血淋巴细胞RNA，经逆转录制备成cDNA，设计特异性引物，用PCR方法从cDNA中扩增Cx26基因，将其定向插入真核表达载体pCI-neo中获得pCI-Cx26重组子-采用酶切法和测序法鉴定。用脂质体将pCI-Cx26转染COS-7细胞，经G418筛选，获得阳性克隆。用RT-PCR和SDS-PAGE检测对表达产物进行检测。结果从人外周血RNA制备而成的cDNA中可扩增出预期大小的Cx26基因片段，pCI-Cx26经双酶切测序证实构建成功。RT-PCR和SDS-PAGE检测到pCI-Cx26在COS-7细胞中获得稳定、高效表达。结论本研究成功构建了人连接蛋白Cx26基因重组真核表达载体pCI-Cx26：pCI-Cx26脂质体转染COS-7细胞，可见Cx26基因在COS-7细胞中获得稳定、高效的表达。该结果为今后进行pCI-Cx26基因治疗Cx26基因突变引起的遗传性耳聋的研究奠定了实验基础。     

抗汉滩病毒中和性鼠/人嵌合抗体基因转化拟南芥的初步研究

目的:建立能表达抗汉滩病毒中和性鼠/人嵌合抗体基因的转基因植株,为汉坦病毒基因工程抗体的研究提供实验基础.方法:将构建的含抗汉滩病毒中和性鼠/人嵌合抗体基因的植物抗体表达质粒3G1MH-pCAMBIA2301,用TSS冻融法导入农杆菌GV3101,利用农杆菌介导的抽真空转基因技术转化野生型拟南芥,获得转基因植株.用PCR、Northern blot检测转基因植株.结果:经PCR分析表明,拟南芥的基因组中有抗汉滩病毒中和性鼠/人嵌合抗体基因整合,并成功获得7株T0代转基因拟南芥.植株提取RNA,经Northern blot分析可见约1 500 bp及800 bp处的目的条带,为编码重、轻链的目的基因.结论:成功地构建了含抗汉滩病毒中和性鼠/人嵌合抗体基因的拟南芥植株,为进一步利用植物表达治疗性抗体奠定了基础.     

重组人bFGF的原核表达及其高效价抗血清的制备

目的 以重组人碱性成纤维生长因子为免疫原，制备高效价抗hbFGF抗血清。方法通过PCR方法改造5’编码区的12个密码子，构建hbFGF’原核表达载体并在大肠杆菌(E．coli)中表达，以纯化的hbFGF、免疫新西兰兔，制备高效价抗血清，用于重组hbFGF、的免疫印迹分析。结果经过改造的hbFGF基因在E．coli中获得较高水平表达。从可溶性部分纯化得到纯度95％以上的重组hbFGF，以该重组蛋白免疫兔子，在二次加强后以间接ELISA检测抗血清效价可达1：512000。免疫印迹分析显示该抗血清与E．coli中表达的重组hbFGF、和标准hbFGF、均有特异性反应，但与某些细菌蛋白存在弱交叉反应，经E．coli菌体蛋白吸附的抗血清，与菌体蛋白的弱交叉反应消失。结论以纯化的重组hbFGF为免疫原制备了高效价的特异性抗血清，经菌体蛋白吸附可消除存在的交叉反应性。     

人、黑猩猩和叶猴FKN全基因的克隆及体外表达的比较研究

目的克隆人、黑猩猩和叶猴FKN全基因及体外表达,比较研究FKN在进化过程中基因组水平和蛋白表达水平的差异。方法应用基因重叠延伸拼接PCR法（Gene splicing by overlapping extension PCR,SOE-PCR）将FKN的3个外显子编码序列依次进行前后拼接,然后插入pcDNA3.1/myc-His（-）A真核表达载体中,经酶切、测序鉴定后转染CHO细胞体外表达,RT-PCR、SDS-PAGE和Western blot检测其表达产物。结果酶切、测序鉴定证实插入的基因片段为完整的FKN,RT-PCR可从转染的CHO细胞中扩增出一条与目的基因大小一致的DNA片段,其表达蛋白能分泌至胞外,SDS-PAGE显示其分子量约为95000,抗c-myc抗体可与载体上的c-myc蛋白特异性结合。测序显示人、黑猩猩和叶猴相比,FKN基因除了有散在的点突变外,还发现有一明显的30bp的缺失,但此缺失对FKN蛋白的表达并不影响。结论成功克隆人、黑猩猩和叶猴FKN全基因,基因组水平和蛋白表达水平的比较研究为后续探讨FKN在高级灵长类物种进化过程中免疫学功能的演变奠定基础。     

二硫键稳定的人源性抗bFGF双链抗体的酵母表达及鉴定

目的为提高小分子抗体表达量,利用酵母表达系统表达二硫键稳定的人源性抗bFGF双链抗体(ds-Diabody)并研究其生物学活性。方法将ds-Diabody基因构建到酵母表达载体中获得重组质粒pPICZαA-ds-Diabody,经BglⅡ线性化电转至毕赤酵母GS115中,甲醇诱导表达。表达产物经SDS-PAGE及Western blot鉴定,并进行镍离子亲和层析和阴离子交换层析纯化。间接ELISA检测其抗原结合活性,CCK8法和划痕实验检验其肿瘤抑制作用。结果成功构建人源性抗bFGF ds-Diabody酵母表达载体,并获得4株高表达酵母工程菌,经1%甲醇诱导96 h表达量即可恒定,表达量可达158 mg/L。SDS-PAGE及Western blot结果显示,目的蛋白大小约Mr35 000左右。通过两步纯化方案,目的蛋白的纯度可达95%以上。ELISA结果显示纯化的ds-Diabody可与bFGF特异性结合。CCK8结果显示,纯化的ds-Diabody可剂量依赖性地抑制人肺癌细胞株A549的增殖,最大抑制率为43.4%。划痕实验表明ds-Diabody可以抑制肿瘤细胞的迁移。结论研究结果表明人源性抗bFGF ds-Diabody在毕赤酵母中可获得高效表达,且具有很好的生物学活性。     

人受精相关抗原-1的基因克隆及原核表达

目的为了阐明免疫性不孕不育的原因,检测血清中存在的抗精子抗体的种类,构建重组人受精相关抗原-1（recombinant human Fertilization antigen-1,rhFA-1）的原核表达质粒并在大肠杆菌中诱导表达。方法采用RT-PCR法,从人睾丸组织总RNA中扩增获得人FA-1的cDNA,将其克隆入表达载体pBV220,构建人源性FA-1的重组原核表达质粒pBV220/FA-1。重组质粒经酶切和测序鉴定后,转化大肠杆菌JM109并在大肠杆菌中诱导表达目的蛋白。结果测序表明重组基因序列与人FA-1基因完全一致。SDS-PAGE电泳显示,表达产物的相对分子量为14.6KDa与预期结果相符。结论获得了人FA-1的编码基因,并在大肠杆菌中表达了人的FA-1蛋白。     

抗CD20嵌合抗体的构建与表达

目的构建抗CD20嵌合抗体的真核表达载体并实现在真核细胞中的表达。方法采用RT-PCR,从分泌鼠源抗人CD20抗体的杂交瘤细胞系1-28中钓取其轻、重链基因,连接至T载体,进行序列测定。还原SDS聚丙烯酰胺凝胶电泳分离抗CD20单克隆抗体(mAb)1-28的轻、重链蛋白,切取轻链及重链条带,质谱测定氨基酸序列,Biolynx和pepeseq软件分析可信度。对比所测DNA序列与蛋白序列,确定所钓取基因的正确性。将mAb1-28轻重链可变区基因,连接至表达载体pCMV-VH和pCMV-VL,构建成嵌合抗体C1-28的轻链真核表达载体C1-28L及重链真核表达载体C1-28H。PCR、酶切及序列测定以确定连入基因的正确性。脂质体介导法将嵌合抗体的轻重链真核表达载体共转染入293T细胞,RT-PCR检测mRNA水平的表达,夹心ELISA法检测蛋白表达量,Westernblot检测目的蛋白的大小。结果钓取到mAb1-28基因。mAb部分蛋白序列测定结果与根据所钓取基因推出的蛋白序列相对应。成功构建了嵌合抗体的真核表达载体,并实现真核表达,表达量可达257mg/L,其相对分子质量(Mr)与人IgG的Mr一致。结论为后续研究嵌合抗CD20抗体对非霍奇金淋巴瘤的治疗提供了一定的依据。     

F10蛋白的原核表达及多克隆抗体的制备

目的：表达F10蛋白，并制备兔抗F10多克隆抗体。方法：利用PCR方法扩增F10基因片段，经BamHⅠ和EcoRⅠ酶切后连接人pET-GST原核表达载体，构建的pET-GST／F10融合重组表达质粒转化大肠杆菌B121，经IPTG诱导表达蛋白，并以亲和层析的方法进行纯化。表达产物用SDS—PAGE电泳和Western blot进行分析鉴定。以纯化的F10蛋白免疫新西兰大白兔，制备兔抗F10的多克隆抗体，并以ELISA法检测抗体效价。结果：经酶切和核酸序列分析证实重组质粒包含有正确编码的F10读码框。SDS—PAGE电泳分析显示pET—GST／F10诱导后表达一相对分子质量（Mr）约为61000的融合蛋白，与预期结果相符。目的蛋白纯化后的纯度达90％以上，Western blot证实该蛋白是GST／F10的融合蛋白。将纯化的GST／F10融合蛋白免疫家兔，得到的兔抗F10抗体效价达1：20000。结论：成功构建了人F10基因原核表达载体，并获得了高纯度的F10重组蛋白及兔抗F10抗体，为下一步研究F10基因功能奠定了实验基础。     

Immunodetection of Canine Parvovirus (CPV) in clinical samples by polyclonal antisera against CPV-VP2 protein expressed in Esherichia coli as an antigen

The entire virion protein 2 (VP2) gene of Canine Parvovirus (CPV) was amplified by polymerase chain reaction (PCR) and engineered to be expressed by a bacterial expression vector pET-28a, under the control of the IPTG-inducible T7lac promoter. SDS-PAGE gel revealed that VP2 expressed as a 67kDa, and found mainly in the pellet of the bacterial lysates, suggesting that cytoplasmic expression is not preferred. The recombinant protein VP2 fused with His-tag was purified from Esherichia coli using Ni-NTA resin under denaturing conditions. SDS-PAGE analysis also showed the high expression of several lower molecular weight (LMW) bands. Western blot analysis showed that polyclonal antisera produced by rabbit against E. coli-VP2 protein reacted specifically with the purified VP2 protein as well as two other LMW bands. Some of the resulting LMW products failed to keep their antigenic site in the N-terminal region of the VP2. The degradation of recombinant VP2 protein in E. coli could be due to the action of host proteases. The immunodetection ability of the polyclonal antisera was compared with that of a commercial monoclonal antibody to test numerous clinical specimens by immuno-dot blot assays. There were distinctive differences in the degree of immunodetection ability of polyclonal antisera and monoclonal antibody to react with CPV antigens. The reaction time of polyclonal antisera was much faster in visual color appearance than that of monoclonal antibody during NBT/BCIP staining. The result from diagnostic PCR assay confirmed the presence of CPV in 44 out of 46 specimens collected, consistent with polyclonal antisera-positive result. Therefore, the polyclonal antisera can be used for CPV detection in the faeces of diarrhoeic dogs, which was found to be more rapid, sensitive, broad but less specific than the monoclonal antibody.     

Determination of the molecular nature and cellular localization of Thy-1 in human renal tissue

The molecular nature and cellular localization of Thy-1 antigen in human renal tissue were studied. Strong immunohistochemical staining was observed in frozen sections of human kidney using monoclonal anti-human Thy-1 antibody; this reaction was almost completely abolished by pretreating the kidney section with phosphatidyl inositol (PI)-specific phospholipase C (PI-PLC). Immunohistochemical analysis revealed that the Thy-1 antigen is localized on the proximal tubular epithelial cells and the Bowman's capsule of the glomerulus. Northern blot analysis of renal mRNA using a cloned human Thy-1 gene revealed the presence of human Thy-1 mRNA of a similar size to the one in human brain. When a human kidney cDNA library was screened with the same probe, a cDNA of human Thy-1 was isolated. Moreover, human Thy-1 protein with a molecular weight (MW) of 21,000 was detected in renal tissue by gel electrophoresis and Western blot analysis using monoclonal anti-human Thy-1 antibody. These data demonstrate for the first time the production of human Thy-1 as a PI-anchored protein with a unique cellular location in human renal tissue.     

黑胸大蠊与美洲大蠊交叉抗原成分比较

对黑胸大蠊与美洲大蠊体部浸出液交叉抗原成分进行分析 ,为利用有关美洲大蠊分子克隆的资料进行黑胸大蠊主要变应原的克隆、测序和重组表达做前期工作。制备纯种黑胸大蠊及美洲大蠊的体部浸出液 ,采用SDS PAGE (12 %分离胶 )分离蛋白成分 ,用Coomassi亮蓝染色 ,比较两种来源蛋白成分的差异。然后将蛋白电转至PVDF膜 ,以兔抗黑胸大蠊体部浸出液 (WBE )抗体作为第一抗体 ,进行Western免疫印迹检测 ,以判断两种蟑螂的交叉抗原成分。两种蟑螂体部浸出液蛋白成分的SDS PAGE带型略有差异 ,主要是条带密度不一致 ,而从其疏密分布 (分布型式 )上看 ,两者间存在相当多的分子量相同或相近组分。经SDS PAGE分离的条带多达近 30条 ,分子量相同的组分多达 2 0余条。免疫印迹表明 ,针对兔抗黑胸大蠊体部浸出液 (WBE )抗体 (IgG )有交叉反应的抗原成分多达 10几条。黑胸大蠊与美洲大蠊体部浸出液的蛋白成分或变应原组分间存在交叉反应成分。提示 ,利用有关美洲大蠊分子克隆的资料进一步对黑胸大蠊主要变应原进行克隆、测序或重组表达等分子生物学研究具备一定的可行性。     

The 200/220 kDa antigen recognized by monoclonal antibody (MAb) UJ127.11 on neural tissues and tumors is the human L1 adhesion molecule

MAb UJ127.11, raised against 16 week human fetal brain, recognizes an antigen present primarily on normal and tumor tissues derived from the neuroectoderm. The antigen has previously been identified as a 220/240 kDa cell surface glycoprotein as determined by immunoprecipitation studies. We show here, that the 220/240 kDa antigen is the human L1 cell adhesion molecule and by Western blot analysis actually has a calculated molecular weight of between 200-220 kDa. Immunocytochemical studies with UJ127.11 and an antibody (5G3) recently utilized to isolate human L1 from brain indicate that both reagents have very similar binding profiles. The binding of radiolabelled UJ127.11 to its target antigen can be blocked by the addition of a rabbit anti-human L1 antiserum. Furthermore, sequential immunoprecipitation and Western blot analysis shows that UJ127.11 and the rabbit anti-human L1 antiserum recognize identical proteins.     

Baculovirus expression, purification and evaluation of recombinant pneumococcal surface adhesin A of Streptococcus pneumoniae.

Pneumococcal surface adhesin A (PsaA), with a molecular mass of approximately 37 kD by SDS-PAGE, is a common surface protein expressed by all 90 serotypes of Streptococcus pneumoniae. S. pneumoniae serotype 6B genomic DNA was amplified to generate a DNA fragment carrying the full-length psaA sequence and was cloned into a baculovirus expression system. We expressed either cell-associated or cell-free nonfusion PsaA polypeptides using two insect cell lines, Spodoptera frugiperda (Sf9) and Trichoplusia ni 5B1-4 (High-Five). Recombinant PsaA (rPsaA) polypeptides were partially purified by partitioning in PBS/Triton X-114 buffers and by weakly basic ion exchange filter chromatography. Membrane-bound 'hydrophobic rPsaA' (hrPsaA) expressed by either Sf9 or High-Five cells had a molecular mass of approximately 38 kD by SDS-PAGE and partitioned in a Triton X-114 phase, it reacted with both rabbit polyclonal and five monoclonal anti-PsaA antibodies by dot blot or Western blot analysis. High-Five-cell-expressed 'soluble rPsaA' (srPsaA) with a molecular mass of approximately 37 kD by SDS-PAGE, was isolated from the serum-free culture medium and did not partition in the Triton X-114 phase; it reacted with anti-PsaA rabbit polyclonal and mouse monoclonal antibodies by ELISA and Western blot analysis. Both rPsaA polypeptide forms were immunogenic in Swiss-Webster adult female mice. In an infant mouse model of bacteremia, survival rates for mice given mouse anti-rPsaA immune serum (from mice immunized with High-Five-expressed srPsaA; 20 microl, 1:50,000 titer) 24 h before bacteremic challenge were greater than for the control group (48 h postchallenge, 20 vs. 90% survival rates) when challenged with S. pneumoniae serotype 6B. These results indicate that rPsaA is immunogenic and elicits protective antibody in mice similar to native protein.     

金黄色葡萄球菌核酸酶在大肠杆菌中的表达及其活性分析

目的:构建金黄色葡萄球菌核酸酶(SN)基因的原核表达载体,研究其在大肠杆菌中的表达,并制备兔抗SN抗体。方法:从质粒pPLCSN中扩增SN基因片段,插入表达载体pLEX后转化大肠杆菌GI724,以色氨酸诱导表达。以表达的重组蛋白免疫日本大耳白兔制备抗SN抗体,用Westernblot分析兔抗SN抗体的特异性。结果:重组表达载体pLEXSN在大肠杆菌中获得表达,表达的可溶性蛋白占菌体蛋白总量的37%,具有良好的生物学活性。制备的兔抗SN抗体能够特异识别SN。结论:成功地在大肠杆菌中表达具有生物学活性的SN,并制备了兔抗SN抗体,为进一步探讨其作为抗病毒因子应用于病毒性疾病的治疗奠定了基础。     

Preparation and characterization of the polyclonal antibody against pig integrin beta6 subunit LBD as FMDV receptor

AIM: To induce the expression of FMDV receptor integrin beta6 subunit ligand-binding domain in E.coli and prepare the rabbit polyclonal antibody against it. METHODS: The fragment coding beta6 ligand-binding domain was amplified by PCR and doubly digested with BamH Iand Xho I. Then it was cloned into expression vector pGEX-4T-1 to obtain recombinant plasmid pGEX-4T-1-beta6LBD. After pGEX-4T-1-beta6LBD was transformed into E.coli BL21(DE3) and induced by IPTG, the expression of fusion proteins was identified by SDS-PAGE, with inclusion body prepared and fusion protein purified. Then new Zealand rabbits were immunized to prepare polyclonal antibody against beta6LBD. GST-beta6LBD antiserum was obtained and the specificity of polyclonal antibody was detected by Western blot. RESULTS: SDS-PAGE demonstrated that the fusion protein GST-beta6LBD was expressed with the expected molecular weight at 42 000. A single clear band of GST-beta6LBD fusion protein appeared in SDS-PAGE gel after purification. The titer of the polyclonal antibody was above 1:12 800 and it is of high specificity. CONCLUSION: The successful preparation of rabbit anti pig beta6LBD polyclonal antibody with high affinity and specificity will lay a foundation for further research into the function of integrin beta6 in FMDV infection.