Temporin-1CEa is an antimicrobial peptide isolated from the skin secretions of the Chinese brown frog Rana chensinensis. It has the amino acid sequence FVDLKKIANIINSIF-NH₂ and shares 50–56% identity with other temporin family peptides from various frog species. Structural analysis reveals that temporin-1CEa adopts a well-defined α-helical conformation in 50% trifluoroethanol/water solution, with an α-helix content of 87.59%. The peptide exhibits amphiphilic properties and a net positive charge, which are characteristic features of membrane-active antimicrobial peptides.

Studies demonstrate that temporin-1CEa displays cytotoxic effects on multiple human carcinoma cell lines, with particularly high activity against breast cancer MCF-7 cells. The peptide's mechanism of action is attributed to its interaction with negatively charged cell membranes, leading to rapid membrane disruption. Notably, temporin-1CEa shows low hemolytic activity against human erythrocytes and minimal cytotoxicity toward normal human cells, suggesting selective targeting of cancer cell membranes.

• Wang C, Li HB, Li S, Tian LL, Shang DJ. Antitumor effects and cell selectivity of temporin-1CEa, an antimicrobial peptide from the skin secretions of the Chinese brown frog (Rana chensinensis). Biochimie. 2012;94(2):434-41.

三氟乙酸（TFA）是一种强酸，常用于从固相树脂中裂解合成的多肽，也可用于提高多肽纯化步骤中的HPLC性能。默认情况下，定制的多肽是以冻干的TFA盐的形式交付的，其中TFA的含量可能高达10-45%。

定制多肽中的TFA可能会导致后续检测数据出现无法解释的差异。例如，nM浓度的TFA已被证明会干扰细胞实验，在某些情况下会抑制细胞增殖，而在其他情况下会增加细胞活力。

TFA去除服务推荐用于:

• 将用于细胞试验的多肽
• 将被用作原料药或制成品的多肽
• 含有大量碱性残基的亲水多肽

干品多肽的重量中不仅仅包含多肽，还包含有一些非肽的组份，如水、被吸收的溶剂、配位离子和盐等。肽的净含量是指肽在其中的重量百分比，这个百分比的数值范围很大，可能从50%到90%，取决于纯度、序列以及合成和纯化的方法，不要将肽的净含量和肽的纯度混为一谈，他们是两个完全不同的概念。纯度通常是通过HPLC测定的。纯度定义的是多肽样品中含正确序列的组分的百分比，而肽的净含量是指样品中肽类物质相对于总物质所占的百分比，肽的净含量通常是氨基酸组分分析或紫外分光法测定的，这个信息主要是在一些对肽的浓度很敏感的实验中，对计算肽的浓度是很重要的。