Quintero Catherine, Rosenstein Craig, Hughes Bethany, Middleton Richard, Kariv Ilona
Merck & Co., Inc., Merck Research Laboratories, Boston, MA 02115, USA.
J Biomol Screen. 2007 Sep;12(6):891-9. doi: 10.1177/1087057107302114. Epub 2007 May 21.
With the advancement of high-throughput biomolecular screening techniques to the lead optimization stage, there is a critical need to quality control (QC) dose-response curves generated by robotic liquid handlers to ensure accurate affinity determinations. One challenge in evaluating the performance of liquid handlers is identifying and validating a robust method for testing dispense volumes across different instruments. Although traditional automated liquid handlers are still considered the standard platform in many laboratories, nanoliter dispensers are becoming more common and pose new challenges for routine quality control procedures. For example, standard gravimetric measurements are unreliable for testing the accuracy of nanoliter liquid dispenses. However, nanoliter dispensing technology allows for the conservation of compound, reduces compound carryover from well to well through discrete dispenses, and eliminates the need for intermediate compound dilution steps to achieve a low final DMSO assay concentration. Moreover, an intermediate dilution step in aqueous solution might result in compound precipitation at high concentrations. This study compared representative automation procedures done on a variety of liquid dispensers, including manual, traditional, and nanodispense volumes. The data confirmed the importance of establishing robust QC procedures for dose-response generation in addition to accuracy and precision determinations for each instrument, and they validated the use of nanoliter pipettors for dose-response testing. The results of this study also support the requirement for thorough mixing during serial compound dilutions prepared for high-throughput lead optimization strategies using traditional liquid handlers.
随着高通量生物分子筛选技术发展到先导化合物优化阶段，迫切需要对机器人液体处理仪生成的剂量反应曲线进行质量控制（QC），以确保准确测定亲和力。评估液体处理仪性能的一个挑战是确定并验证一种可靠的方法来测试不同仪器的分液体积。尽管传统的自动液体处理仪在许多实验室中仍被视为标准平台，但纳升分液仪正变得越来越普遍，给常规质量控制程序带来了新的挑战。例如，标准重量法测量对于测试纳升液体分液的准确性并不可靠。然而，纳升分液技术可以节省化合物，通过离散分液减少孔间的化合物残留，并且无需进行中间化合物稀释步骤即可实现低最终二甲基亚砜（DMSO）测定浓度。此外，在水溶液中进行中间稀释步骤可能会导致高浓度下化合物沉淀。本研究比较了在各种液体分液仪上进行的代表性自动化程序，包括手动、传统和纳升分液体积。数据证实了除了对每台仪器进行准确性和精密度测定外，还需要建立可靠的QC程序来生成剂量反应曲线，并且验证了使用纳升移液器进行剂量反应测试的可行性。本研究结果还支持在使用传统液体处理仪为高通量先导化合物优化策略制备系列化合物稀释液时进行充分混合的要求。
