電(dian)泳儀是(shi)實現(xian)(xian)電(dian)泳分析的儀器。電(dian)泳是(shi)一種帶電(dian)分子(zi)在電(dian)場中向著電(dian)性(xing)相反的電(dian)極移動的現(xian)(xian)象(xiang)。利用電(dian)泳現(xian)(xian)象(xiang)進行物質分離(li)的技(ji)術,稱電(dian)泳技(ji)術。
自從1946年瑞(rui)典物理(li)化(hua)學家Tiselius教(jiao)授研制(zhi)的(de)第一臺商(shang)品化(hua)移界(jie)電(dian)(dian)(dian)泳系統問世以來(lai),電(dian)(dian)(dian)泳分(fen)析(xi)儀(yi)發(fa)展極其迅(xun)速。特別是隨著(zhu)支(zhi)持介質(zhi)的(de)更新,各種各樣的(de)電(dian)(dian)(dian)泳分(fen)析(xi)裝置相(xiang)繼推出(chu),以適應不(bu)同國家實驗室進行教(jiao)學、臨床和科(ke)研工作的(de)需要(yao)(yao)。20世紀70年代(dai)以來(lai),已有越來(lai)越多的(de)自動化(hua)電(dian)(dian)(dian)泳分(fen)析(xi)儀(yi)相(xiang)繼被(bei)引入臨床實驗室,并在各種疾病(bing)的(de)臨床診治中發(fa)揮著(zhu)越來(lai)越重要(yao)(yao)的(de)作。
1.早期階(jie)段(~1970年以(yi)前)
支持介(jie)質有醋(cu)酸纖維素薄膜(簡稱醋(cu)纖膜)及瓊脂糖凝(ning)膠(jiao)兩大類(lei),這一時(shi)期的(de)電泳分析儀(yi)多用于蛋(dan)(dan)白質如血(xue)清(qing)蛋(dan)(dan)白、脂蛋(dan)(dan)白、血(xue)紅蛋(dan)(dan)白等項目分析。
2.中期(qi)階段(1970年(nian)~1990年(nian))
這一時(shi)期(qi)電泳分析儀主要是可(ke)見光(guang)/熒光(guang)雙系統自動電泳掃(sao)描儀,熒光(guang)試劑與熒光(guang)掃(sao)描儀的推出,在臨床上極(ji)大地方便了乳(ru)酸(suan)(suan)脫氫(qing)酶(LD)和(he)肌酸(suan)(suan)激(ji)酶(CK)同(tong)工(gong)酶的測定。
3.發展階段(1990年~至(zhi)今)
這一(yi)時期(qi)電(dian)(dian)泳(yong)(yong)(yong)分析儀(yi)以(yi)自(zi)(zi)動化為最大變化特(te)點。常見有全(quan)(quan)自(zi)(zi)動熒光(guang)/可見光(guang)雙系(xi)統電(dian)(dian)泳(yong)(yong)(yong)儀(yi)、全(quan)(quan)自(zi)(zi)動醋纖膜(mo)電(dian)(dian)泳(yong)(yong)(yong)儀(yi)、全(quan)(quan)自(zi)(zi)動瓊脂糖電(dian)(dian)泳(yong)(yong)(yong)儀(yi)等幾類。
在(zai)溶液中能吸(xi)附帶(dai)電(dian)(dian)(dian)(dian)質(zhi)點或(huo)本身帶(dai)有(you)可解離基(ji)團(tuan)的(de)(de)(de)(de)物(wu)(wu)質(zhi)顆粒(li),如蛋(dan)白質(zhi)、氨基(ji)酸等,在(zai)一(yi)定(ding)(ding)的(de)(de)(de)(de)pH值(zhi)條件(jian)下(xia),于直流電(dian)(dian)(dian)(dian)場(chang)中必然會受到電(dian)(dian)(dian)(dian)性相反的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)極吸(xi)引而發生移動。不同(tong)物(wu)(wu)質(zhi)的(de)(de)(de)(de)顆粒(li)在(zai)電(dian)(dian)(dian)(dian)場(chang)中的(de)(de)(de)(de)移動速度除與其(qi)帶(dai)電(dian)(dian)(dian)(dian)狀態和(he)電(dian)(dian)(dian)(dian)場(chang)強(qiang)度有(you)關外,還(huan)與顆粒(li)的(de)(de)(de)(de)大(da)小、形狀和(he)介(jie)質(zhi)黏(nian)度有(you)關。根據(ju)這一(yi)特征,應用(yong)電(dian)(dian)(dian)(dian)泳(yong)法便(bian)可以對不同(tong)物(wu)(wu)質(zhi)進(jin)(jin)行定(ding)(ding)性或(huo)定(ding)(ding)量分(fen)析,或(huo)將一(yi)定(ding)(ding)混合物(wu)(wu)進(jin)(jin)行組分(fen)分(fen)析或(huo)單(dan)個組分(fen)提(ti)取制(zhi)(zhi)備,電(dian)(dian)(dian)(dian)泳(yong)儀(yi)正是基(ji)于上述原理(li)設(she)計(ji)制(zhi)(zhi)造的(de)(de)(de)(de)。
電泳的(de)影響因素很(hen)多,主要有被分(fen)離物(wu)質的(de)帶電荷(he)量多少、電場強度、緩沖液的(de)pH值(zhi)和離子強度及支持(chi)介質的(de)化學惰性。
常(chang)用(yong)電(dian)泳設備的(de)基本(ben)結構包括(kuo):電(dian)源、電(dian)泳槽及附(fu)加裝置。
根據(ju)電泳(yong)中是否使用支持介質分為自由電泳(yong)和(he)區帶電泳(yong)。
自(zi)由(you)(you)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)不使用(yong)支持介質,電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)在溶液(ye)中(zhong)進(jin)行。這類電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)又分為非(fei)自(zi)由(you)(you)界(jie)(jie)面(mian)(mian)(mian)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)和自(zi)由(you)(you)界(jie)(jie)面(mian)(mian)(mian)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)兩類。非(fei)自(zi)由(you)(you)界(jie)(jie)面(mian)(mian)(mian)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)指懸浮在溶液(ye)中(zhong)的(de)帶電(dian)(dian)(dian)(dian)粒(li)子(如各種細胞)通電(dian)(dian)(dian)(dian)后全(quan)部(bu)移動,不出現界(jie)(jie)面(mian)(mian)(mian),如顯微電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)等。自(zi)由(you)(you)界(jie)(jie)面(mian)(mian)(mian)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)中(zhong)被分離物質集中(zhong)在某一(yi)層,形成各自(zi)的(de)界(jie)(jie)面(mian)(mian)(mian)而進(jin)行定性或定量分析。自(zi)由(you)(you)界(jie)(jie)面(mian)(mian)(mian)電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)需要昂貴(gui)精密的(de)電(dian)(dian)(dian)(dian)流(liu)儀器,僅在少數特殊電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)如等電(dian)(dian)(dian)(dian)聚焦電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)和等速電(dian)(dian)(dian)(dian)泳(yong)(yong)(yong)(yong)中(zhong)使用(yong)。
區帶電泳(yong)(yong)(yong)都使用支持(chi)介質,根據(ju)支持(chi)介質不同分為濾紙電泳(yong)(yong)(yong)、醋纖膜(mo)電泳(yong)(yong)(yong)、薄層電泳(yong)(yong)(yong)和(he)凝膠(jiao)電泳(yong)(yong)(yong)等。此外(wai),根據(ju)支持(chi)介質的裝置形(xing)(xing)式不同又可(ke)分為水平板式電泳(yong)(yong)(yong)、垂直板式電泳(yong)(yong)(yong)、垂直盤狀電泳(yong)(yong)(yong)、毛細管電脈、橋形(xing)(xing)電泳(yong)(yong)(yong)和(he)連續(xu)流動電泳(yong)(yong)(yong)等。
常見(jian)的幾種(zhong)電(dian)泳儀有(you):
1.全自動熒光/可見光雙系統電泳(yong)儀
具有熒(ying)(ying)光(guang)/可見光(guang)雙系統,使(shi)用(yong)熒(ying)(ying)光(guang)試劑項目(mu)如CK、LD同工酶。優點(dian)靈敏度、準確度高且采用(yong)高壓、低溫系統,速度非常快。
2.全自動醋纖膜(mo)電(dian)泳儀
為(wei)可(ke)見光單系(xi)統(tong),使用(yong)醋纖膜電泳片,優點為(wei)自動化程(cheng)度更(geng)高。多(duo)用(yong)于臨床常規血清蛋白電泳分析。
3.全自動瓊脂糖電泳儀(yi)
為(wei)可見(jian)光單(dan)系統,使(shi)用瓊脂糖(tang)凝膠電泳(yong)膠片,優(you)點為(wei)靈敏度高,可用于低(di)濃度蛋白(bai)檢驗,如尿蛋白(bai)及腦(nao)脊液蛋白(bai),同工酶的分離效果(guo)也相當不(bu)錯,所(suo)能(neng)做項目(mu)較(jiao)多(duo)且靈敏度較(jiao)高。
4.全自動電泳分析系統
該(gai)電(dian)泳(yong)儀集中了上述儀器的優點(dian),自(zi)動點(dian)樣、電(dian)泳(yong)、呈(cheng)色(或染(ran)色、脫(tuo)色)、烘干(gan)。可(ke)用(yong)各種(zhong)電(dian)泳(yong)片,包(bao)括瓊(qiong)脂(zhi)片、醋(cu)酸片、聚丙烯酰胺等,采(cai)用(yong)可(ke)見光及熒光呈(cheng)色雙系(xi)統,是一種(zhong)較理想(xiang)的電(dian)泳(yong)儀。
對不同物質進(jin)行定性(xing)或(huo)定量分析,或(huo)將一定混合物進(jin)行組分分析或(huo)單個組分提(ti)取制備,應用于臨床醫學的實驗(yan)室檢驗(yan)或(huo)科研(yan)實驗(yan)研(yan)究。
1.首(shou)先用導線將(jiang)電泳(yong)槽(cao)的兩個電極與(yu)電泳(yong)儀的直流輸出端聯接(jie),注(zhu)意極性(xing)不要接(jie)反。
2.電(dian)泳儀電(dian)源開關(guan)調至關(guan)的位置(zhi),電(dian)壓旋鈕轉(zhuan)到最小(xiao),根據工作需要(yao)選擇(ze)穩(wen)壓穩(wen)流(liu)方式(shi)及電(dian)壓電(dian)流(liu)范圍。
3.接通電(dian)源(yuan),緩(huan)緩(huan)旋轉電(dian)壓調節鈕(niu)直到(dao)達到(dao)的所(suo)需電(dian)壓為止,設(she)定電(dian)泳(yong)終(zhong)止時間,此時電(dian)泳(yong)即開始(shi)進行(xing)。
4.工作(zuo)完畢后,應將各旋鈕、開(kai)關(guan)(guan)旋至零(ling)位或關(guan)(guan)閉狀(zhuang)態,并(bing)撥出電泳插頭。
1.電(dian)泳儀通電(dian)進入工作狀態后,禁(jin)止人體接觸電(dian)極(ji)、電(dian)泳物及其它可能(neng)帶電(dian)部分,也不(bu)能(neng)到電(dian)泳槽內取放東西(xi),如需(xu)要應(ying)先斷(duan)電(dian),以免觸電(dian)。同時要求(qiu)儀器必須(xu)有(you)良(liang)好(hao)接地(di)端(duan),以防漏電(dian)。
2.儀器通電后,不要(yao)臨時增加或撥除輸出導線插(cha)頭,以防短路(lu)現象發生,雖然儀器內部附(fu)設(she)有(you)保險絲,但(dan)短路(lu)現象仍有(you)可(ke)能導致儀器損壞。
3.由于(yu)不同(tong)介質(zhi)(zhi)支持(chi)物的電(dian)(dian)阻值不同(tong),電(dian)(dian)泳時所(suo)通過(guo)的電(dian)(dian)流量也不同(tong),其泳動(dong)速度及泳至(zhi)終點所(suo)需時間也不同(tong),故不同(tong)介質(zhi)(zhi)支持(chi)物的電(dian)(dian)泳不要(yao)同(tong)時在同(tong)一電(dian)(dian)泳儀上進行。
4.在總電流(liu)(liu)不超過儀器(qi)(qi)額定電流(liu)(liu)時(最大(da)電流(liu)(liu)范圍),可以(yi)多槽關聯使用,但(dan)要注(zhu)意不能(neng)超載,否則容(rong)易影(ying)響儀器(qi)(qi)壽命(ming)。
5.某些特殊(shu)情況下需檢查(cha)儀器(qi)電(dian)泳輸(shu)入情況時,允(yun)許在穩壓狀(zhuang)態下空載開機,但在穩流(liu)狀(zhuang)態下必(bi)須先接好負載再開機,否則電(dian)壓表指針將大幅度(du)跳動,容易造成不必(bi)要的人為機器(qi)損壞。
6.使用過程(cheng)中發(fa)現異常現象,如較大噪音、放電或異常氣味,須立(li)即切斷(duan)電源,進行檢修,以(yi)免發(fa)生意外事(shi)故。
1.電泳儀(yi)的輸出達(da)不到設定值
電(dian)泳(yong)儀(yi)的輸出值狀態遵循“歐姆定律”:電(dian)壓U=電(dian)流I×(電(dian)泳(yong)槽(cao))電(dian)阻R
電阻R相對不變(bian)的情況下,U、I、P(功率P=電流I×電壓(ya)U)中(zhong)任意1個(ge)參數(shu)恒(heng)定(ding),其(qi)他(ta)參數(shu)也(ye)隨(sui)之恒(heng)定(ding);而任意1個(ge)參數(shu)變(bian)化,其(qi)他(ta)參數(shu)也(ye)隨(sui)之正比(bi)變(bian)化。
如(ru)果(guo)電(dian)(dian)泳(yong)儀的(de)輸(shu)出電(dian)(dian)壓U達(da)(da)不到預置值,應首先觀察I或(huo)P是否(fou)已(yi)經(jing)(jing)恒(heng)定,或(huo)者已(yi)經(jing)(jing)達(da)(da)到電(dian)(dian)泳(yong)儀所規定的(de)最大I或(huo)P(JY電(dian)(dian)泳(yong)儀均有明確(que)指示燈標志)。如(ru)果(guo)尚未(wei)達(da)(da)到極(ji)限值,將(jiang)已(yi)經(jing)(jing)恒(heng)定I或(huo)P的(de)設置調大(有必要(yao)的(de)話(hua)至極(ji)限值),才能夠提高電(dian)(dian)壓輸(shu)出。
如果電(dian)(dian)(dian)泳(yong)儀的(de)電(dian)(dian)(dian)流I達(da)不(bu)到(dao)預置值,可(ke)調整電(dian)(dian)(dian)壓U或功(gong)率P。如果電(dian)(dian)(dian)泳(yong)儀的(de)功(gong)率P達(da)不(bu)到(dao)預置值,可(ke)調整電(dian)(dian)(dian)壓U或電(dian)(dian)(dian)流I。
2.電腦控制電泳儀(yi)過(guo)壓報(bao)警
(1)檢查是否空載(zai)使用。
(2)是否電泳槽未(wei)加緩沖(chong)液。
(3)是否電泳槽鉑金絲斷。
3.過流保護
(1)是否(fou)存在(zai)電泳(yong)槽短路現象。
(2)緩(huan)沖(chong)液是(shi)否選(xuan)錯(cuo)。
4.漏電保護
(1)是否有液體濺(jian)入儀(yi)器內(nei)部或輸出接口上。
(2)是否有很多灰塵落入儀器內(nei)部。