Invitrogen™ ReadyCount™ Stains 

Description

ReadyCount stains are fluorescent cell stains specifically optimized for use on the Countess II FL and Countess 3 FL automated cell counters. These benchtop-stable reagents are ready-to-use nuclear stains that can be mixed 1:1 with cell samples. They are designed for fast and easy counting of nucleated cells and isolated nuclei, enabling increased accuracy using fluorescence-based count mode when counting mixed cell populations or samples containing cellular debris.

Features of the fluorescent ReadyCount stains:

• Accurate—eliminates the error involved with creating stock solutions and dilution series
• Flexible—optimized for use in both Countess II FL and Countess 3 FL automated cell counters equipped with DAPI, GFP, RFP, or Texas Red (TxR) light cubes
• Fast—stains cells in < 5 minutes
• Convenient—store on your benchtop, no freezing/thawing required, use by mixing 1:1 v/v with cell sample
• Versatile—stain and count nucleated cells or isolated nuclei for RNA sequencing and gene expression applications in single-cell analysis workflows

ReadyCount stains work in three simple steps:

• Mix 10 μL of cell sample with 10 μL of ReadyCount stain and incubate up to 5 minutes
• Pipet 10 μL of the stained cell sample into a Countess chamber slide
• Insert the slide into the Countess instrument

Obtain accurate cell counts

The fluorescent ReadyCount reagents allow for the specific staining of nucleated cells within a mixed population, thereby reducing complexity and improving count-to-count and sample-to-sample repeatability in automated cell counting when matched to the appropriate EVOS™ light cube.

Improve downstream single-cell analysis

Accurate viable cell counts are crucial when performing RNA sequencing and single-cell analysis. Staining with fluorescent ReadyCount stains and using the Countess™ 3 FL-based count mode enables detection of all fluorescent objects, resulting in more accurate counts and viability measurements for samples with debris or out of focus cells in brightfield. Characterization of isolated nuclei is also required for scATAC-Seq, a method for studying genome-wide chromatin accessibility. To accurately count isolated nuclei, it is recommended to use fluorescent ReadyCount stains instead of trypan blue. Trypan blue can lead to overcounting of nuclei due to debris staining.

The fluorescent ReadyCount stain options include:

• ReadyCount Red Dead Cell Stain is a benchtop-stable red fluorescent stain optimized for staining dead nucleated cells in Countess II FL or Countess 3 FL automated cell counters. Traditional visible red filter sets such as the EVOS RFP or Texas Red light cubes are suitable for use with the ReadyCount Red Dead Cell Stain (propidium iodide).
• ReadyCount Blue Nuclear Stain is a benchtop-stable blue fluorescent stain optimized for staining nucleated cells in Countess II FL or Countess 3 FL automated cell counters. Traditional DAPI filter sets such as the EVOS DAPI light cube are suitable for use with the ReadyCount Blue Nuclear Stain (Hoechst 33342).
• ReadyCount Green/Red Dead Viability Stain is a benchtop-stable green and red fluorescent stain combination optimized for staining nucleated cells to measure viability in Countess II FL or Countess 3 FL automated cell counters. Traditional FITC or GFP filter sets such as the EVOS GFP light cube are suitable for exciting and detecting the green stain (acridine orange), while the EVOS Texas Red (TxR) light cube is suitable for the red cell stain (propidium iodide). Green denotes live cells while red represents dead cells. Because these dyes only stain nucleated cells, the ReadyCount Green/Red Dead Viability Stain is useful for obtaining accurate counts of viable cells for RNA sequencing and single-cell analysis.