ELISA试剂盒的制备有必要标准化

<p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><font face="宋体">在试验条件（包含试剂）较难保证稳定的情况下，这种判别法较为适宜。在得出标本（</font>S<font face="宋体">）和阴性对照（</font><font face="Calibri">N</font><font face="宋体">）的</font><font face="Calibri">A</font><font face="宋体">值后，核算</font><font face="Calibri">S/N</font><font face="宋体">值。也有写作</font><font face="Calibri">P/N</font><font face="宋体">的，这里的</font><font face="Calibri">P</font><font face="宋体">不代表阳性（</font><font face="Calibri">positive</font><font face="宋体">），而是病（</font><font face="Calibri">patient</font><font face="宋体">）的缩写，不该误解。为防止混杂，更宜用</font><font face="Calibri">S/N</font><font face="宋体">表示。在早期的间接法</font><font face="Calibri">ELISA</font><font face="宋体">试剂盒中，有些作者定出</font><font face="Calibri">S/N</font><font face="宋体">为阳性规范，现多为各种测定所沿袭。</font></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><font face="宋体">实际上每一测定体系应该用试验求出各自的</font>S/N<font face="宋体">的阈值。更应留意的是，</font><font face="Calibri">N</font><font face="宋体">所代表的阴性对照是不含受检物质的人血清。有的试剂盒中所设阴性对照为不含蛋白质或蛋白质含量较底的缓冲液，致使反响后发生的本底也许较正常人血清的本底低得多。阳性断定值（</font><font face="Calibri">cut-off value</font><font face="宋体">）通常为阴性对照</font><font face="Calibri">A</font><font face="宋体">值加上一个特定的常数，以此作为判别结果阳性或阴性的规范。</font></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p class="MsoNormal"><strong><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;">ELISA<font face="宋体">试剂盒</font></span></strong><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><font face="宋体">用此法判别结果请求试验条件非常稳定，阳性和阴性的对照品应契合必定的标准，须配用精密的仪器，并严厉按规定操作。阳性断定值公式中的常数是在这特定的体系中经过对很多标本的试验检查而得到的。</font></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><font face="宋体">现举某种检查</font>HBsAg<font face="宋体">的试剂盒为例。试剂盒中的阴性对照品为不含</font><font face="Calibri">HBsAg</font><font face="宋体">的复钙人血浆，阳性对照品</font><font face="Calibri">HBsAg</font><font face="宋体">的含量标明为</font><font face="Calibri">P=9</font><font face="宋体">&plusmn;</font><font face="Calibri">2ng/ml</font><font face="宋体">。每次试验设</font><font face="Calibri">2</font><font face="宋体">个阳性对照和</font><font face="Calibri">3</font><font face="宋体">个阴性对照。测得</font><font face="Calibri">A</font><font face="宋体">值后，先核算阴性对照</font><font face="Calibri">A</font><font face="宋体">值的平均数（</font><font face="Calibri">NCX</font><font face="宋体">）和阳性对照</font><font face="Calibri">A</font><font face="宋体">值的平均数（</font><font face="Calibri">PCX</font><font face="宋体">），两个平均数的差（</font><font face="Calibri">P-N</font><font face="宋体">）有必要大于一个特定的数值（例</font><font face="Calibri">0.400</font><font face="宋体">），试验才有用。</font></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;">3<font face="宋体">个阴性对照</font><font face="Calibri">A</font><font face="宋体">值均应&ge;</font><font face="Calibri">0.5</font><font face="宋体">&times;</font><font face="Calibri">NCX</font><font face="宋体">，并&le;</font><font face="Calibri">1.5</font><font face="宋体">&times;</font><font face="Calibri">NCX</font><font face="宋体">，如其中之一超出此规模，则弃去，罢了另两个阴性对照从头核算</font><font face="Calibri">NCX</font><font face="宋体">；如有两个阴性对照</font><font face="Calibri">A</font><font face="宋体">值超出以上规模，则该次试验无效。</font></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p class="MsoNormal"><span style="color: rgb(255, 0, 0);"><strong><span style="font-family: 宋体; font-size: 9pt;"><font face="宋体">阳性断定值按下式核算：</font></span></strong></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"> </span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p class="MsoNormal"><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><font face="宋体">阳性断定值</font>=NCX+0.05 <font face="宋体">标本</font><font face="Calibri">A</font><font face="宋体">值＞阳性断定值的为阳性，小于阳性断定值的为阴性。应留意的是，式中</font><font face="Calibri">0.05</font><font face="宋体">为该试剂盒的常数，只适合于该特定条件下，</font><font face="Calibri">ELISA</font><font face="宋体">试剂盒而不是对各种试剂均可通用。</font></span><span style="mso-spacerun:'yes';font-family:宋体;mso-ascii-font-family:Calibri;mso-hansi-font-family:Calibri;mso-bidi-font-family:'Times New Roman';font-size:9.0000pt;mso-font-kerning:1.0000pt;"><o:p></o:p></span></p> <p>&nbsp;</p>