Bright at 24 h but signal rapidly decays at 48 – 72 h (Transfection)

Question

Accepted Answer

Early time point shows strong fluorescence but it drops sharply within 48 – 72 h; signal varies dramatically between time points. Common causes: 1) Transient transfection inherently shows short-lived expression 2) Cell division dilutes the plasmid 3) Promoter silencing leads to unstable expression 4) Wrong observation window chosen for the assay Solutions: 1) Choose the right observation window for your system (typically 24 – 48 h for transient) 2) Match the imaging time point to your functional readout 3) For long-term experiments, consider stable selection (puromycin, G418) or lentiviral delivery 4) Record a full time-course curve rather than relying on a single time point