Interferon (IFN), the first ever-described cytokine, has a potent activity against viruses. Soon since its discovery, quantification of IFN has been an important issue. Most of the traditional methods to measure IFN biological activity rely on indirect methods that quantify dyes retained by IFN-protected cells against a lytic virus, or by techniques that indirectly quantify viral replication by measuring the expression level of viral-encoded reporter proteins such as the green fluorescent protein (GFP). In both cases, the IFN units are determined by the quantification of an effective dose 50, defined as the IFN dose that prevents 50% cell death of 50% reduction of the maximal amount of GFP intensity. In this study we propose the use of an alternative approach to measure IFN activity by calculating the minimal IFN dose 50 as the amount of IFN able to completely protect 50% of the cells from infection measured by the total absence of virus-dependent GFP signal in a cell culture plate. This sensitive approach could be used to easily quantify the Z value to determine IFN bioassay robustness. We believe that this approximation could be interesting to be considered by the IFN community.

中文翻译：

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一种量化I型干扰素的数字方法。

干扰素（IFN）是有史以来第一个描述的细胞因子，对病毒具有有效的活性。自发现以来，IFN的量化一直是重要的问题。大多数测量IFN生物学活性的传统方法都依赖于间接方法，该方法可以量化被IFN保护的细胞针对裂解病毒保留的染料，或者通过测量病毒编码的报告蛋白（例如SNP）的表达水平来间接量化病毒复制的技术。绿色荧光蛋白（GFP）。在这两种情况下，IFN单位均通过有效剂量50的定量来确定，有效剂量50被定义为可防止GFP强度最大量减少50％的50％细胞死亡的IFN剂量。在这项研究中，我们建议使用另一种方法来测量IFN的活性，方法是通过计算最小IFN剂量50，即通过完全不存在病毒依赖性GFP信号而测得的能够完全保护50％细胞免受感染的IFN的量。细胞培养板。这种灵敏的方法可用于轻松量化Z值，以确定IFN生物测定的鲁棒性。我们认为，这种近似可能会引起IFN社区的关注。