Bacigalupo M A, Meroni G, Secundo F, Lelli R
Istituto di Chimica del Riconoscimento Molecolare, CNR, Via M. Bianco 9, Milan 20131, Italy.
Talanta. 2008 Oct 19;77(1):126-30. doi: 10.1016/j.talanta.2008.05.057. Epub 2008 Jun 12.
In this paper, we have reported an immunoassay with time-resolved revelation system for ampicillin in raw milk samples. Immunological methods appear to be a promising approach in the analysis of beta-lactam compounds, because they do not need previous sample pre-treatments. In fact, beta-lactam ring is not very stable in extensive sample pre-treatment procedures requested in conventional analytical techniques. Specimens were collected from lactating cows bred in various conditions and assayed for the fat contents. Ampicillin was assayed in samples with different fat concentrations. The assay was performed using ampicillin-specific polyclonal antibody raised in rabbit; the immunogen was synthesized using bovine thyroglobulin conjugated to ampicillin by glutaraldehyde reaction; as fluorescent marker we used goat anti-rabbit IgG conjugated with a chelating molecule complexed with Eu(3+). Bovine serum albumin (BSA) conjugated with ampicillin was synthesized and used to prepare a solid phase on polystyrene microtiter plates. The use of a lanthanide chelate as label allowed to achieve 1 ng mL(-1) sensitivity, which is four times more sensitive than limits requested from European Community. Fat contents did not affect the assay performance.
在本文中，我们报道了一种用于生鲜乳样品中氨苄西林检测的具有时间分辨显色系统的免疫分析方法。免疫分析方法在β-内酰胺类化合物分析中似乎是一种很有前景的方法，因为它们无需事先对样品进行预处理。事实上，在传统分析技术所要求的广泛样品预处理过程中，β-内酰胺环不是很稳定。从在各种条件下饲养的泌乳奶牛采集样本，并对其脂肪含量进行测定。对不同脂肪浓度的样品中的氨苄西林进行检测。检测使用在兔体内产生的氨苄西林特异性多克隆抗体；免疫原通过戊二醛反应将氨苄西林与牛甲状腺球蛋白偶联合成；作为荧光标记物，我们使用与与铕（Eu(3+)）络合的螯合分子偶联的山羊抗兔IgG。合成了与氨苄西林偶联的牛血清白蛋白（BSA），并用于在聚苯乙烯微量滴定板上制备固相。使用镧系螯合物作为标记物可实现1 ng mL(-1)的灵敏度，这比欧盟要求的限值灵敏四倍。脂肪含量不影响检测性能。
