電(dian)(dian)泳(yong)儀是實現(xian)電(dian)(dian)泳(yong)分(fen)析的儀器。電(dian)(dian)泳(yong)是一種帶電(dian)(dian)分(fen)子在(zai)電(dian)(dian)場(chang)中(zhong)向著電(dian)(dian)性相反的電(dian)(dian)極移動的現(xian)象。利用電(dian)(dian)泳(yong)現(xian)象進行(xing)物質分(fen)離的技術(shu),稱(cheng)電(dian)(dian)泳(yong)技術(shu)。
自(zi)從1946年瑞典物理化(hua)學家Tiselius教(jiao)授研制的第一臺商品化(hua)移界(jie)電泳(yong)系(xi)統問世(shi)(shi)以(yi)來(lai),電泳(yong)分(fen)析(xi)儀(yi)發(fa)展極其迅速。特別(bie)是隨(sui)著支持介質的更(geng)新,各(ge)種各(ge)樣的電泳(yong)分(fen)析(xi)裝置相繼推出(chu),以(yi)適應不同國(guo)家實驗室(shi)進行教(jiao)學、臨床(chuang)(chuang)和科研工作的需要(yao)。20世(shi)(shi)紀70年代以(yi)來(lai),已有越(yue)(yue)來(lai)越(yue)(yue)多的自(zi)動化(hua)電泳(yong)分(fen)析(xi)儀(yi)相繼被引入臨床(chuang)(chuang)實驗室(shi),并在各(ge)種疾病的臨床(chuang)(chuang)診(zhen)治中發(fa)揮著越(yue)(yue)來(lai)越(yue)(yue)重要(yao)的作。
1.早期階段(~1970年(nian)以前)
支持介質有醋酸纖(xian)維素薄(bo)膜(簡稱醋纖(xian)膜)及(ji)瓊(qiong)脂糖凝膠兩大類,這一時期的電(dian)泳分析(xi)儀多用(yong)于(yu)蛋(dan)白(bai)(bai)質如(ru)血(xue)清蛋(dan)白(bai)(bai)、脂蛋(dan)白(bai)(bai)、血(xue)紅蛋(dan)白(bai)(bai)等(deng)項目(mu)分析(xi)。
2.中期(qi)階段(1970年(nian)~1990年(nian))
這(zhe)一時期電(dian)泳分(fen)析(xi)儀主要(yao)是可見光/熒(ying)光雙系統(tong)自(zi)動(dong)電(dian)泳掃描(miao)儀,熒(ying)光試劑與熒(ying)光掃描(miao)儀的推出,在(zai)臨床上(shang)極(ji)大地方便了乳(ru)酸脫(tuo)氫酶(LD)和肌酸激酶(CK)同工酶的測定。
3.發展階段(duan)(1990年~至今)
這一時期電泳分(fen)析儀(yi)以(yi)自(zi)動化為最(zui)大變化特點(dian)。常見(jian)有全(quan)自(zi)動熒光/可見(jian)光雙系統(tong)電泳儀(yi)、全(quan)自(zi)動醋纖(xian)膜電泳儀(yi)、全(quan)自(zi)動瓊(qiong)脂糖(tang)電泳儀(yi)等幾類(lei)。
在溶液中(zhong)能吸(xi)附帶電(dian)(dian)質(zhi)(zhi)點或(huo)本身帶有(you)可解離基(ji)團的(de)物質(zhi)(zhi)顆粒,如蛋白質(zhi)(zhi)、氨基(ji)酸等,在一(yi)定(ding)(ding)的(de)pH值條件下,于直流(liu)電(dian)(dian)場中(zhong)必然會受(shou)到(dao)電(dian)(dian)性相(xiang)反的(de)電(dian)(dian)極(ji)吸(xi)引而發生(sheng)移(yi)動。不(bu)同(tong)物質(zhi)(zhi)的(de)顆粒在電(dian)(dian)場中(zhong)的(de)移(yi)動速(su)度除與(yu)其帶電(dian)(dian)狀態和電(dian)(dian)場強度有(you)關(guan)外,還(huan)與(yu)顆粒的(de)大小、形狀和介質(zhi)(zhi)黏度有(you)關(guan)。根據這一(yi)特征,應用(yong)電(dian)(dian)泳法便(bian)可以對不(bu)同(tong)物質(zhi)(zhi)進(jin)行(xing)定(ding)(ding)性或(huo)定(ding)(ding)量分(fen)(fen)析(xi),或(huo)將一(yi)定(ding)(ding)混合物進(jin)行(xing)組(zu)分(fen)(fen)分(fen)(fen)析(xi)或(huo)單個組(zu)分(fen)(fen)提取制備,電(dian)(dian)泳儀(yi)正是(shi)基(ji)于上述原理設計制造的(de)。
電泳的影響因素很多,主要有(you)被(bei)分離物質的帶電荷量多少、電場(chang)強度、緩(huan)沖液(ye)的pH值和離子(zi)強度及支(zhi)持介質的化學惰性(xing)。
常用電(dian)(dian)泳設備的基本結構包括:電(dian)(dian)源、電(dian)(dian)泳槽(cao)及附加裝置。
根據電(dian)泳(yong)中是否使用支持介質分(fen)為(wei)自由電(dian)泳(yong)和(he)區帶電(dian)泳(yong)。
自(zi)(zi)由(you)(you)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)不使用支持介質,電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)在(zai)(zai)溶液(ye)中(zhong)進行(xing)。這類(lei)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)又分為非自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)和(he)自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)兩類(lei)。非自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)指懸浮在(zai)(zai)溶液(ye)中(zhong)的(de)帶電(dian)(dian)(dian)(dian)粒子(如(ru)(ru)各種(zhong)細胞)通電(dian)(dian)(dian)(dian)后全(quan)部移動,不出現界(jie)(jie)面,如(ru)(ru)顯微電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)等。自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)中(zhong)被分離物質集(ji)中(zhong)在(zai)(zai)某一層,形成各自(zi)(zi)的(de)界(jie)(jie)面而進行(xing)定性(xing)或定量分析。自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)需要昂貴精(jing)密的(de)電(dian)(dian)(dian)(dian)流儀器,僅在(zai)(zai)少數特殊電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)如(ru)(ru)等電(dian)(dian)(dian)(dian)聚焦電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)和(he)等速電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)(yong)中(zhong)使用。
區(qu)帶電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)都使(shi)用支(zhi)持(chi)介(jie)質(zhi)(zhi),根據支(zhi)持(chi)介(jie)質(zhi)(zhi)不同分為濾紙電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)、醋纖膜電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)、薄層電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)和凝膠電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)等。此外(wai),根據支(zhi)持(chi)介(jie)質(zhi)(zhi)的裝置形(xing)式(shi)(shi)不同又可分為水平板(ban)式(shi)(shi)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)、垂直(zhi)板(ban)式(shi)(shi)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)、垂直(zhi)盤(pan)狀電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)、毛(mao)細管(guan)電(dian)(dian)(dian)(dian)脈、橋形(xing)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)和連(lian)續流動(dong)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)等。
常(chang)見(jian)的幾種(zhong)電泳儀有:
1.全自動熒光/可見光雙系統電泳儀
具(ju)有(you)熒(ying)光/可見光雙系統,使(shi)用(yong)熒(ying)光試劑項目如CK、LD同工酶。優點(dian)靈敏(min)度、準確度高且采用(yong)高壓、低(di)溫系統,速(su)度非常快。
2.全自動醋纖膜(mo)電(dian)泳儀
為可見光(guang)單(dan)系統,使(shi)用醋纖膜電泳片,優(you)點為自動(dong)化程(cheng)度更高。多用于臨床(chuang)常規血清蛋白電泳分(fen)析(xi)。
3.全自(zi)動瓊脂糖(tang)電泳儀
為可見光單系統,使用瓊脂糖凝膠電泳膠片(pian),優點為靈(ling)敏度高,可用于低濃度蛋(dan)白檢(jian)驗(yan),如尿蛋(dan)白及腦(nao)脊液(ye)蛋(dan)白,同工酶的分離效(xiao)果(guo)也相當不錯,所能做項目(mu)較多且靈(ling)敏度較高。
4.全自動(dong)電泳分(fen)析系統
該電(dian)泳(yong)儀(yi)集中了上(shang)述儀(yi)器的優點,自動點樣、電(dian)泳(yong)、呈(cheng)色(se)(se)(或染色(se)(se)、脫色(se)(se))、烘干。可用各種(zhong)電(dian)泳(yong)片,包括瓊脂片、醋酸片、聚丙烯(xi)酰胺等(deng),采用可見光(guang)及熒(ying)光(guang)呈(cheng)色(se)(se)雙系統,是一種(zhong)較理想的電(dian)泳(yong)儀(yi)。
對不同(tong)物質進行定性或定量(liang)分析(xi),或將一定混合物進行組分分析(xi)或單個組分提取制備,應用于臨床醫(yi)學的(de)實驗室檢(jian)驗或科(ke)研(yan)實驗研(yan)究。
1.首先(xian)用(yong)導線將電(dian)泳槽(cao)的兩(liang)個電(dian)極與(yu)電(dian)泳儀的直流輸出端聯接,注意極性不要接反(fan)。
2.電(dian)(dian)(dian)泳儀電(dian)(dian)(dian)源開(kai)關調至(zhi)關的位置,電(dian)(dian)(dian)壓旋鈕轉到最小,根據工(gong)作需要選擇穩(wen)壓穩(wen)流(liu)方(fang)式及電(dian)(dian)(dian)壓電(dian)(dian)(dian)流(liu)范圍。
3.接通電(dian)源,緩緩旋轉電(dian)壓調節(jie)鈕(niu)直到達到的(de)所需電(dian)壓為止,設定電(dian)泳(yong)(yong)終止時(shi)間,此(ci)時(shi)電(dian)泳(yong)(yong)即開始進行。
4.工作完畢后,應(ying)將(jiang)各旋(xuan)鈕、開關旋(xuan)至零(ling)位或關閉(bi)狀態,并(bing)撥出電泳(yong)插(cha)頭(tou)。
1.電(dian)(dian)(dian)泳儀通(tong)電(dian)(dian)(dian)進入工作狀態后,禁止人體接觸電(dian)(dian)(dian)極(ji)、電(dian)(dian)(dian)泳物及(ji)其它(ta)可能帶電(dian)(dian)(dian)部分,也不(bu)能到電(dian)(dian)(dian)泳槽內取(qu)放東(dong)西,如需要應先斷電(dian)(dian)(dian),以免觸電(dian)(dian)(dian)。同時要求儀器必須有良(liang)好接地端(duan),以防漏電(dian)(dian)(dian)。
2.儀器(qi)通電(dian)后,不要臨時增(zeng)加或撥除輸(shu)出導線(xian)插頭,以防短路(lu)現象發生,雖(sui)然儀器(qi)內部附(fu)設有保險絲,但短路(lu)現象仍有可(ke)能導致儀器(qi)損(sun)壞(huai)。
3.由于不同介質支持物的電阻值不同,電泳時所通過(guo)的電流(liu)量也不同,其泳動速(su)度及(ji)泳至終(zhong)點所需時間也不同,故不同介質支持物的電泳不要同時在同一電泳儀上進行。
4.在總電流不超過儀(yi)器(qi)額定電流時(shi)(最大電流范圍),可以多槽關聯使用(yong),但要(yao)注意不能超載,否則容易影響儀(yi)器(qi)壽命。
5.某些特殊情(qing)況下(xia)(xia)需檢查儀(yi)器電(dian)泳輸入情(qing)況時,允許在穩壓狀態下(xia)(xia)空載開機,但在穩流狀態下(xia)(xia)必(bi)須先接好負載再開機,否則電(dian)壓表指針將大幅度跳動,容易(yi)造成不必(bi)要的人為(wei)機器損壞(huai)。
6.使(shi)用過(guo)程中發現(xian)異(yi)常現(xian)象(xiang),如(ru)較大噪音、放電或異(yi)常氣味,須立即切斷(duan)電源,進(jin)行(xing)檢(jian)修(xiu),以免發生意外(wai)事(shi)故。
1.電泳儀的輸出達(da)不(bu)到設定(ding)值(zhi)
電(dian)(dian)泳儀的輸出(chu)值狀(zhuang)態遵循“歐姆定(ding)律”:電(dian)(dian)壓U=電(dian)(dian)流I×(電(dian)(dian)泳槽)電(dian)(dian)阻R
電(dian)阻(zu)R相(xiang)對不變(bian)的情況下,U、I、P(功率P=電(dian)流I×電(dian)壓U)中(zhong)任(ren)意1個參(can)數(shu)(shu)恒定,其(qi)他(ta)參(can)數(shu)(shu)也隨之(zhi)(zhi)恒定;而(er)任(ren)意1個參(can)數(shu)(shu)變(bian)化(hua),其(qi)他(ta)參(can)數(shu)(shu)也隨之(zhi)(zhi)正(zheng)比變(bian)化(hua)。
如(ru)(ru)果(guo)電(dian)(dian)泳儀(yi)的(de)輸出電(dian)(dian)壓U達不(bu)到預置(zhi)值,應首先(xian)觀(guan)察I或P是否已(yi)經恒(heng)定(ding),或者已(yi)經達到電(dian)(dian)泳儀(yi)所規定(ding)的(de)最(zui)大I或P(JY電(dian)(dian)泳儀(yi)均有明確指(zhi)示燈標志)。如(ru)(ru)果(guo)尚未達到極(ji)限(xian)值,將已(yi)經恒(heng)定(ding)I或P的(de)設置(zhi)調大(有必要的(de)話至(zhi)極(ji)限(xian)值),才(cai)能(neng)夠提高電(dian)(dian)壓輸出。
如(ru)果(guo)電(dian)泳儀(yi)的電(dian)流I達不到預置值,可(ke)調整電(dian)壓(ya)U或功率P。如(ru)果(guo)電(dian)泳儀(yi)的功率P達不到預置值,可(ke)調整電(dian)壓(ya)U或電(dian)流I。
2.電腦控制電泳(yong)儀(yi)過壓報警
(1)檢(jian)查是否空載使用(yong)。
(2)是否(fou)電泳槽未加緩沖液(ye)。
(3)是否電泳槽鉑金絲斷。
3.過流保護
(1)是否存在電(dian)泳槽(cao)短路現(xian)象。
(2)緩沖(chong)液是否(fou)選錯。
4.漏電保護
(1)是否(fou)有液體濺入儀器內(nei)部或輸出(chu)接口上(shang)。
(2)是否有很多灰塵(chen)落(luo)入儀器(qi)內(nei)部。