Wadsworth C, Nilsson L A, Bjursten L M
J Immunol Methods. 1983 Aug 26;62(2):217-29. doi: 10.1016/0022-1759(83)90249-1.
Precipitation profiles of spot immunoprecipitate assay (SIA) reactions in gel are shown to have characteristics analogous to classic precipitin curves representing such immune reactions in solution. Thus SIA profiles of precipitated human albumin (HSA) and anti-HSA as checkerboard analysis permit: (1) determination of optimal proportions of antibody and antigen, (2) titration of antiserum as to antigen-binding capacity and (3) estimation of the concentration of specific antibody in an antiserum. The validity of the method was confirmed by similar results already reported for precipitin analysis of anti-HSA in solution. The stained protein assay method for determination of total protein used for the calculations had a reliable (r = 0.9979) working range for quantification between 0.1 and 0.83 microgram protein in 3 microliters samples (greater than or equal to 0.03 g/l). Study of SIA profiles in the extreme antibody excess region confirmed the validity of SIA quantification. The high sensitivity of SIA as compared with radial immunodiffusion is related to high ratios (8-9) of antibody to antigen; the reliable detection limit for SIA is 10 mg/l in a 3 microliters sample. SIA is easy to perform with simple laboratory equipment, allows measurement of any precipitable antigen with very small amounts of reactants, and gives results within an hour.
凝胶中斑点免疫沉淀试验（SIA）反应的沉淀图谱显示出与代表溶液中此类免疫反应的经典沉淀素曲线相似的特征。因此，作为棋盘分析的沉淀人白蛋白（HSA）和抗HSA的SIA图谱可以：（1）确定抗体和抗原的最佳比例，（2）对抗血清的抗原结合能力进行滴定，以及（3）估计抗血清中特异性抗体的浓度。该方法的有效性已通过先前报道的溶液中抗HSA沉淀素分析的类似结果得到证实。用于计算的总蛋白测定的染色蛋白测定方法在3微升样品（大于或等于0.03克/升）中定量的可靠工作范围为0.1至0.83微克蛋白（r = 0.9979）。对极端抗体过量区域的SIA图谱研究证实了SIA定量的有效性。与放射免疫扩散相比，SIA的高灵敏度与抗体与抗原的高比例（8 - 9）有关；SIA在3微升样品中的可靠检测限为10毫克/升。SIA使用简单的实验室设备即可轻松进行，允许用极少量的反应物测量任何可沉淀的抗原，并在一小时内得出结果。
