Member since: 2017
Organization: Mayo Clinic
NucLight Rapid Red reagent formulation change is not good for MSC assaying.
Application Area: Imaging cell count with nuclear stain
"I have been using the NucLight Rapid Red Reagent (Catalog#4717) for staining adipose derived MSC since 2018. Up until a change in formulation of the reagent by Essen Bioscience, which occurred in February 2019, the reagent worked extremely well. The signal was bright and very well contained within the cell nuclei of proliferating mesenchymal stem cell (MSC) over the course of 3-5 day culture. After the change in the formulation, the signal brightness has been reduced by 5-10-fold, making the ease of use to quantify cell count by nuclear stain extremely difficult. This change in reagent formulation impacted the signal seen in proliferating MSC culture, thereby necessitating more frequent changes to the analysis mask applied to the scans within the file obtained by the IncuCyte S3 Live-Cell Imaging System. These high-through-put imaging systems are meant to be used with limited changes to the system inputs so that one can compare results which are dependent on the cells being assayed and independent of technician or reagent variable. In order to have reproducibility in science, one must have confidence in the quality and integrity of the reagents purchased from the manufacturer. Please start producing NucLight Rapid Red Reagent with the formulation that was relevant for Lot number 18N0501-110718 or earlier! Mesenchymal Stem Cells are very sensitive to the culture media, supplement and reagents used to assay their proliferation capacity so changing this NucLight Rapid Red Reagent formulation was a big deal."
The Incucyte® NucLight Rapid Red Reagent for cell labeling is a cell permeable DNA stain that specifically stains nuclei in live cells and is ideally suited to the mix-and-read, real-time quantification of cell counting.
Addition of the Incucyte® NucLight Rapid Red Reagent to normal healthy cells is non-perturbing to cell growth and morphology and provides homogenous staining of nuclei. When added to tissue culture medium, the inert stain crosses the cell membrane and has excellent specificity for DNA without the need for a wash step.
With the Incucyte® integrated analysis software, fluorescent objects can be quantified and background fluorescence minimized. This reagent can be multiplexed with Incucyte® Annexin V, Caspase-3/7 or Cytotox reagents for simultaneous readouts of apoptosis or cytotoxicity alongside cell proliferation.