Anicetti V, Hancock W S
Genentech, Inc., South San Francisco, California.
Bioprocess Technol. 1994;18:11-36.
Successful and rapid process development requires the availability of suitable analytical methods at all stages of the development cycle (see Tables 2 and 3). The methods should be selected first to ensure the identity, potency, and purity of the product and second to facilitate the process development. Some assays are particularly valuable early in the recovery process (and early in the development cycle) because they are typically robust and can be used with crude samples that contain many components. Popular examples include SDS-PAGE, IEF, and immunoassay, which allow the process scientist simply to monitor the yield and removal of impurities on a broad scale. Each step should be monitored with a biological assay, so that the specific activity of the target protein can be followed and steps that cause a loss of activity can be quickly detected. At the end of the recovery process (and development cycle) more sophisticated analytical methods, for example RP-HPLC and mass spectrometry, are used to detect and characterize variants of the desired product. Highly process-specific assays, such as host cell impurity ELISAs, are developed at this point, and the key methods for process monitoring and final product characterization are selected. While each process development project is distinct, in all cases the use of well-validated complementary analytical methods will provide greater assurance of a timely and successful project.
成功且快速的工艺开发要求在开发周期的各个阶段都具备合适的分析方法（见表2和表3）。首先应选择能确保产品的鉴别、效价和纯度的方法，其次应选择有助于工艺开发的方法。有些分析方法在回收过程早期（以及开发周期早期）特别有价值，因为它们通常稳健，可用于含有多种成分的粗样品。常见的例子包括SDS-PAGE、IEF和免疫分析，这些方法能让工艺科学家简单地从宏观上监测产量和杂质去除情况。每一步都应用生物分析进行监测，以便追踪目标蛋白的比活性，并能快速检测出导致活性丧失的步骤。在回收过程结束时（以及开发周期结束时），会使用更复杂的分析方法，如反相高效液相色谱法（RP-HPLC）和质谱分析法，来检测和鉴定所需产品的变体。此时会开发高度针对特定工艺的分析方法，如宿主细胞杂质酶联免疫吸附测定法（ELISA），并选择用于工艺监测和最终产品鉴定的关键方法。虽然每个工艺开发项目都各不相同，但在所有情况下，使用经过充分验证的互补分析方法将更有把握确保项目及时且成功。
