Why transfect purified proteins directly?
Why transfect purified proteins directly?
Protein transfection is extremely rapid compared to traditional gene expression studies using transfected DNA (1–2 hours compared to 18–48 hours) because it bypasses the cellular processes of transcription and translation. It also facilitates studies involving transient effects of proteins, and avoids potentially harmful, random DNA integration into the genome of the target cells. Xfect Protein Transfection Reagent makes it possible to deliver active proteins directly into cells for studies that involve transcriptional regulation, the cell cycle, apoptosis, oncogenesis, epigenetics, cell regeneration, and transdifferentiation.
Complete induction of an early apoptosis event within 2 hours via protein transfection of active caspase-3. Apoptosis is commonly detected using annexin V-FITC staining (see our ApoAlert Annexin V-FITC Apoptosis Kit, Cat. # 630109), which detects translocation of phosphatidylserine from the inner (cytoplasmic) leaflet of the plasma membrane to the outer (cell surface) leaflet soon after the induction of apoptosis. Annexin V-FITC staining is detected by the ?ow cytometric measurement of increased fluorescence intensity (Panels A and B). We transfected human recombinant caspase-3 using Xfect Protein Transfection Reagent and detected completion of apoptosis after just 2 hr, demonstrating that protein transfection using the Xfect protein reagent is both fast and delivers active protein (Panel B). In comparison, other methods for inducing apoptosis require 12 hr for completion of Annexin V staining (Martin et al. 1995).
Reference
Martin, S. J. et al. Early redistribution of plasma membrane phosphatidylserine is a general feature of apoptosis regardless of the initiating stimulus: inhibition by overexpression of Bcl-2 and Abl. J. Exp. Med. 182, 1545–56 (1995).