電(dian)泳(yong)儀(yi)是(shi)實現(xian)電(dian)泳(yong)分(fen)析的儀(yi)器。電(dian)泳(yong)是(shi)一(yi)種帶電(dian)分(fen)子在電(dian)場(chang)中向著電(dian)性相反的電(dian)極移動(dong)的現(xian)象(xiang)。利用電(dian)泳(yong)現(xian)象(xiang)進行(xing)物質分(fen)離(li)的技術(shu),稱電(dian)泳(yong)技術(shu)。
自(zi)(zi)從1946年瑞(rui)典物(wu)理化學家Tiselius教(jiao)授研制(zhi)的(de)(de)第一臺商品(pin)化移(yi)界電(dian)泳系統問世以(yi)來,電(dian)泳分析(xi)(xi)儀發(fa)展極其迅速(su)。特別是隨(sui)著支持(chi)介(jie)質的(de)(de)更(geng)新,各(ge)種各(ge)樣(yang)的(de)(de)電(dian)泳分析(xi)(xi)裝置相繼推(tui)出(chu),以(yi)適應不同國家實(shi)驗室進行教(jiao)學、臨(lin)床和科研工作(zuo)(zuo)的(de)(de)需(xu)要。20世紀70年代以(yi)來,已有越(yue)來越(yue)多的(de)(de)自(zi)(zi)動化電(dian)泳分析(xi)(xi)儀相繼被引入(ru)臨(lin)床實(shi)驗室,并在各(ge)種疾(ji)病的(de)(de)臨(lin)床診治中(zhong)發(fa)揮著越(yue)來越(yue)重要的(de)(de)作(zuo)(zuo)。
1.早(zao)期階(jie)段(~1970年(nian)以前)
支持介(jie)質有醋酸纖(xian)維素薄膜(簡稱醋纖(xian)膜)及瓊(qiong)脂糖凝膠兩大(da)類(lei),這一時期的電泳(yong)分析(xi)儀(yi)多(duo)用于蛋(dan)白(bai)質如血清(qing)蛋(dan)白(bai)、脂蛋(dan)白(bai)、血紅蛋(dan)白(bai)等項(xiang)目(mu)分析(xi)。
2.中期階段(1970年~1990年)
這一時(shi)期電(dian)泳分析(xi)儀(yi)主要是可見光(guang)(guang)/熒(ying)光(guang)(guang)雙系(xi)統自(zi)動電(dian)泳掃(sao)描(miao)儀(yi),熒(ying)光(guang)(guang)試(shi)劑與(yu)熒(ying)光(guang)(guang)掃(sao)描(miao)儀(yi)的(de)推出,在(zai)臨床上極大地方(fang)便了乳酸脫氫酶(mei)(LD)和肌酸激酶(mei)(CK)同工酶(mei)的(de)測定。
3.發展(zhan)階段(1990年(nian)~至今)
這一時期電(dian)(dian)泳分析儀以自(zi)動(dong)(dong)化(hua)為最(zui)大(da)變化(hua)特點。常見(jian)有全自(zi)動(dong)(dong)熒光/可見(jian)光雙系統電(dian)(dian)泳儀、全自(zi)動(dong)(dong)醋纖膜電(dian)(dian)泳儀、全自(zi)動(dong)(dong)瓊脂糖電(dian)(dian)泳儀等幾(ji)類(lei)。
在溶液中能吸附帶電(dian)質(zhi)(zhi)點或(huo)(huo)本身(shen)帶有(you)可(ke)解離基團的物(wu)(wu)質(zhi)(zhi)顆(ke)粒,如蛋白質(zhi)(zhi)、氨基酸等,在一(yi)定(ding)的pH值條件下,于(yu)直流電(dian)場中必然會受(shou)到(dao)電(dian)性相反(fan)的電(dian)極吸引(yin)而(er)發生移動(dong)。不同(tong)物(wu)(wu)質(zhi)(zhi)的顆(ke)粒在電(dian)場中的移動(dong)速(su)度(du)除與其帶電(dian)狀(zhuang)態和電(dian)場強度(du)有(you)關外,還與顆(ke)粒的大小、形狀(zhuang)和介質(zhi)(zhi)黏度(du)有(you)關。根(gen)據(ju)這一(yi)特征(zheng),應用電(dian)泳(yong)法便可(ke)以對不同(tong)物(wu)(wu)質(zhi)(zhi)進行(xing)(xing)定(ding)性或(huo)(huo)定(ding)量(liang)分析(xi),或(huo)(huo)將一(yi)定(ding)混(hun)合物(wu)(wu)進行(xing)(xing)組分分析(xi)或(huo)(huo)單個組分提取制備,電(dian)泳(yong)儀正是基于(yu)上(shang)述原(yuan)理(li)設計(ji)制造的。
電泳(yong)的影響(xiang)因素很多(duo),主(zhu)要(yao)有被分離物質的帶電荷量多(duo)少、電場(chang)強度、緩沖液的pH值和(he)離子強度及支持介(jie)質的化學(xue)惰性(xing)。
常用電泳設(she)備的基本(ben)結構包括(kuo):電源、電泳槽及(ji)附加裝置。
根(gen)據電泳中是否使用支持介質(zhi)分為自由電泳和區帶電泳。
自(zi)(zi)由(you)(you)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)不使用支持介質(zhi),電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)在(zai)溶液(ye)中進行(xing)。這類電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)又分為非自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)和(he)自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)兩類。非自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)指(zhi)懸(xuan)浮在(zai)溶液(ye)中的(de)帶(dai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)粒子(如各種細胞)通電(dian)(dian)(dian)(dian)(dian)(dian)(dian)后全部(bu)移動,不出現界(jie)(jie)面,如顯微電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)等(deng)(deng)。自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)中被分離物質(zhi)集中在(zai)某一(yi)層,形成各自(zi)(zi)的(de)界(jie)(jie)面而進行(xing)定性或定量(liang)分析。自(zi)(zi)由(you)(you)界(jie)(jie)面電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)需要昂貴精密的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流儀器,僅在(zai)少(shao)數特(te)殊電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)如等(deng)(deng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)聚(ju)焦電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)和(he)等(deng)(deng)速(su)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)中使用。
區帶電(dian)泳(yong)(yong)(yong)(yong)都(dou)使用(yong)支(zhi)持(chi)介(jie)質,根據(ju)支(zhi)持(chi)介(jie)質不(bu)(bu)同(tong)分為濾紙電(dian)泳(yong)(yong)(yong)(yong)、醋(cu)纖(xian)膜電(dian)泳(yong)(yong)(yong)(yong)、薄層電(dian)泳(yong)(yong)(yong)(yong)和凝膠電(dian)泳(yong)(yong)(yong)(yong)等(deng)(deng)。此外,根據(ju)支(zhi)持(chi)介(jie)質的裝置形式不(bu)(bu)同(tong)又可(ke)分為水(shui)平(ping)板式電(dian)泳(yong)(yong)(yong)(yong)、垂(chui)直板式電(dian)泳(yong)(yong)(yong)(yong)、垂(chui)直盤狀電(dian)泳(yong)(yong)(yong)(yong)、毛細管電(dian)脈、橋形電(dian)泳(yong)(yong)(yong)(yong)和連續(xu)流(liu)動電(dian)泳(yong)(yong)(yong)(yong)等(deng)(deng)。
常見的幾種電泳儀有:
1.全自動熒光(guang)/可見光(guang)雙系統(tong)電泳儀
具有熒(ying)光/可見光雙(shuang)系統,使用熒(ying)光試劑項(xiang)目如CK、LD同工酶。優(you)點靈敏度(du)、準(zhun)確度(du)高且采用高壓、低溫(wen)系統,速度(du)非常快。
2.全自(zi)動醋纖膜電泳(yong)儀
為可見光單系統,使用醋纖膜電(dian)泳(yong)片,優(you)點(dian)為自(zi)動(dong)化程度更高。多用于(yu)臨床常(chang)規(gui)血清蛋白(bai)電(dian)泳(yong)分析。
3.全自(zi)動瓊脂糖電泳儀(yi)
為可見光單系(xi)統,使(shi)用(yong)瓊(qiong)脂糖凝膠電(dian)泳膠片,優點為靈敏(min)度(du)(du)高,可用(yong)于低(di)濃度(du)(du)蛋白(bai)(bai)檢驗(yan),如尿蛋白(bai)(bai)及腦脊液(ye)蛋白(bai)(bai),同工酶的分離(li)效果也(ye)相當不錯,所能做項目(mu)較多(duo)且靈敏(min)度(du)(du)較高。
4.全(quan)自動電泳分析(xi)系(xi)統
該電(dian)泳(yong)(yong)儀(yi)集中(zhong)了上述儀(yi)器(qi)的優點(dian),自動點(dian)樣、電(dian)泳(yong)(yong)、呈(cheng)(cheng)色(se)(或染色(se)、脫色(se))、烘干。可(ke)用各(ge)種電(dian)泳(yong)(yong)片(pian),包括瓊脂片(pian)、醋酸(suan)片(pian)、聚丙烯酰胺等,采用可(ke)見光及(ji)熒光呈(cheng)(cheng)色(se)雙(shuang)系(xi)統,是一種較理想的電(dian)泳(yong)(yong)儀(yi)。
對不同物質進行定(ding)性(xing)或(huo)定(ding)量分(fen)(fen)析,或(huo)將一定(ding)混合物進行組分(fen)(fen)分(fen)(fen)析或(huo)單個組分(fen)(fen)提取制備,應用于臨(lin)床醫(yi)學(xue)的(de)實驗室檢(jian)驗或(huo)科研(yan)實驗研(yan)究(jiu)。
1.首先用導(dao)線將電泳槽的(de)兩個電極與電泳儀的(de)直流輸出(chu)端(duan)聯(lian)接,注意(yi)極性不要接反。
2.電(dian)泳儀電(dian)源開關調至關的(de)位置,電(dian)壓(ya)旋鈕轉到(dao)最(zui)小,根據工作(zuo)需要選擇穩壓(ya)穩流方(fang)式及(ji)電(dian)壓(ya)電(dian)流范(fan)圍。
3.接(jie)通電(dian)源,緩(huan)(huan)緩(huan)(huan)旋(xuan)轉電(dian)壓(ya)調節鈕直到達到的所需(xu)電(dian)壓(ya)為止,設定電(dian)泳(yong)(yong)終止時間,此(ci)時電(dian)泳(yong)(yong)即開始進行。
4.工作(zuo)完畢后,應將各旋鈕、開關(guan)旋至(zhi)零位或(huo)關(guan)閉狀態,并(bing)撥出電(dian)泳插頭。
1.電(dian)泳(yong)儀通電(dian)進入工(gong)作狀態后(hou),禁止人體接(jie)觸電(dian)極、電(dian)泳(yong)物及(ji)其(qi)它可能(neng)帶電(dian)部分(fen),也不(bu)能(neng)到電(dian)泳(yong)槽內取放東(dong)西,如需要應先斷電(dian),以免觸電(dian)。同時要求儀器必須有良(liang)好接(jie)地端,以防漏電(dian)。
2.儀器(qi)通電后,不要臨時增加或撥(bo)除輸出(chu)導(dao)(dao)線插頭(tou),以防短(duan)路現象(xiang)(xiang)發(fa)生,雖然儀器(qi)內部(bu)附(fu)設有(you)保險絲,但(dan)短(duan)路現象(xiang)(xiang)仍有(you)可能導(dao)(dao)致儀器(qi)損壞(huai)。
3.由于不(bu)同(tong)(tong)(tong)介(jie)質(zhi)(zhi)支持物的電(dian)(dian)阻值不(bu)同(tong)(tong)(tong),電(dian)(dian)泳(yong)時(shi)所(suo)通過的電(dian)(dian)流(liu)量也(ye)不(bu)同(tong)(tong)(tong),其(qi)泳(yong)動速(su)度及(ji)泳(yong)至終點(dian)所(suo)需時(shi)間也(ye)不(bu)同(tong)(tong)(tong),故(gu)不(bu)同(tong)(tong)(tong)介(jie)質(zhi)(zhi)支持物的電(dian)(dian)泳(yong)不(bu)要同(tong)(tong)(tong)時(shi)在(zai)同(tong)(tong)(tong)一電(dian)(dian)泳(yong)儀(yi)上進行。
4.在總電流(liu)不(bu)超過儀器(qi)額(e)定電流(liu)時(shi)(最(zui)大(da)電流(liu)范圍),可以多槽關(guan)聯(lian)使用,但要注(zhu)意不(bu)能超載,否則容易(yi)影(ying)響(xiang)儀器(qi)壽命(ming)。
5.某(mou)些特殊(shu)情(qing)況下需檢查儀器電泳輸(shu)入情(qing)況時(shi),允許在穩(wen)壓狀態下空載開機,但在穩(wen)流(liu)狀態下必須先接(jie)好負載再開機,否則電壓表指針將大幅度跳動,容(rong)易造(zao)成(cheng)不必要的人為(wei)機器損壞。
6.使用過程中發現(xian)異常(chang)現(xian)象,如(ru)較(jiao)大噪音、放(fang)電或(huo)異常(chang)氣味,須立即切斷電源,進行(xing)檢修,以免發生意(yi)外事故。
1.電泳(yong)儀的輸出達不到設定值(zhi)
電(dian)(dian)泳儀的輸出值狀態遵循“歐姆定(ding)律(lv)”:電(dian)(dian)壓(ya)U=電(dian)(dian)流(liu)I×(電(dian)(dian)泳槽)電(dian)(dian)阻(zu)R
電(dian)阻R相(xiang)對(dui)不變的情況下,U、I、P(功率P=電(dian)流I×電(dian)壓U)中任(ren)意(yi)1個(ge)參數(shu)恒(heng)(heng)定,其他參數(shu)也隨之(zhi)(zhi)恒(heng)(heng)定;而任(ren)意(yi)1個(ge)參數(shu)變化,其他參數(shu)也隨之(zhi)(zhi)正比變化。
如果電泳(yong)儀(yi)(yi)(yi)的輸出(chu)電壓(ya)U達(da)不到預置(zhi)值,應首先觀察(cha)I或(huo)(huo)P是(shi)否已(yi)經(jing)恒(heng)定,或(huo)(huo)者已(yi)經(jing)達(da)到電泳(yong)儀(yi)(yi)(yi)所規定的最大I或(huo)(huo)P(JY電泳(yong)儀(yi)(yi)(yi)均有明(ming)確指示(shi)燈(deng)標志)。如果尚(shang)未達(da)到極(ji)(ji)限(xian)(xian)值,將已(yi)經(jing)恒(heng)定I或(huo)(huo)P的設置(zhi)調大(有必要的話至極(ji)(ji)限(xian)(xian)值),才能夠提(ti)高電壓(ya)輸出(chu)。
如(ru)果電(dian)泳儀的電(dian)流(liu)I達不(bu)到預(yu)置值,可調整(zheng)電(dian)壓U或功(gong)率(lv)P。如(ru)果電(dian)泳儀的功(gong)率(lv)P達不(bu)到預(yu)置值,可調整(zheng)電(dian)壓U或電(dian)流(liu)I。
2.電(dian)腦控制電(dian)泳(yong)儀過壓報警(jing)
(1)檢查是否空載(zai)使用。
(2)是否電泳槽(cao)未加緩沖液。
(3)是(shi)否電泳(yong)槽鉑金絲斷。
3.過流保護
(1)是否存在電泳槽短路現象(xiang)。
(2)緩沖液是否選錯。
4.漏電保護
(1)是(shi)否有液(ye)體(ti)濺入儀器內部或輸出接口上。
(2)是(shi)否有很多(duo)灰塵落入儀器內(nei)部。