本研究欲了解Cell Counting Kit-8 (CCK-8) (Dojindo)是否可應用於檢測秋夜盜蛾 Sf9細胞株(Spodoptera frugiperda, Sf9 cell line)的生長與細胞活性變化。實驗設計是分別考量不同的細胞數量、CCK-8添加量及作用反應時間等條件，分組進行測試反應，並利用酵素免疫自動分析儀(ELISA reader)測定細胞培養液與CCK-8試劑混合液的波長450~620 nm吸光值，作為分析Sf9細胞株生長活性變化的依據。實驗結果顯示添加 CCK-8試劑作用後的Sf9細胞仍可繼續正常生長，並不影響其活性；所需的CCK-8劑量約只需50μL及2小時的作用時間，即可進行吸光值偵測，故CCK-8確實可應用於檢測 Sf9細胞株的存活與增生變化，且操作簡便快速，且不影響利用昆蟲細胞所執行的相關實驗進展與觀察。本研究亦發現CCK-8的呈色反應與活細胞數量間成正比關係。 The aim of this study was to evaluate the feasibility of the cell viability and proliferation of Spodoptera frugiperda, Sf9 cell line by utilizing the Cell Counting kit-8 (CCK-8) (Dojindo). We designed and test different experimental groups according to the numbers of Sf9 cells, the dosage of CCK-8 solution and reaction time, respectively. The absorbance of the mixture of cell culture media and CCK-8 solution was measured at 450nm with an ELISA reader. Our study showed that the Sf9 cells were still viable after adding CCK-8. The absorbance of 450 nm could be measured with only adding 50 µL CCK-8 reagent and 2-hr reaction period. Therefore, the CCK-8 assay may be considered as a faster and useful method for examining the viability and proliferation of Sf9 cells, and wouldn’t interfere the experiment proceeded in the cells. This study also found that the amount of the dye generated by activity of dehydrogenase was directly proportional to the number of living Sf9 cells.