Unique Immunodensity Cell Isolation

RosetteSep™ is a fast and easy immunodensity procedure for the isolation of untouched cells directly from whole blood. By crosslinking unwanted cells to red blood cells (RBCs) present in the sample, target cells are purified during standard density gradient centrifugation (i.e., PBMC isolation using Lymphoprep™, Ficoll-Paque® , RosetteSep™ DM-L Density Medium or RosetteSep™ DM-M Density Medium). This approach significantly reduces sample handling time and maximizes convenience by incorporating cell subset isolation into the centrifugation process.
RosetteSep™ is easily combined with SepMate™ to increase sample throughput and eliminate user errors associated with improper sample layering or PBMC harvesting. This allows users with minimal training to consistently perform cell isolation by density gradient centrifugation and is an ideal fit for a busy laboratory environment.

How to Isolate Cells Directly from Blood with RosetteSep™

To isolate purified cell subsets from whole blood, simply incubate your sample with the appropriate RosetteSep™ cocktail for 20 minutes. Next, layer the sample on a density gradient medium, such as Lymphoprep™, Ficoll-Paque®, etc., and centrifuge for 20 minutes. After centrifugation is complete, collect the untouched cell subset from the interface between the plasma and the density gradient medium.

Overview of All Column-Free Cell Isolation Platforms

How Does RosetteSep™ Work?

  • Unwanted cells are crosslinked to RBCs by specific antibodies forming dense immunorosettes.
  • During density gradient centrifugation immunorosettes pellet, leaving untouched and purified target cells at the interface between the plasma and the density gradient medium.
  • No columns or magnets are necessary. Just incubate, spin, and collect purified cells.

See RosetteSep™ Protocol

Why Use RosetteSep™?

  • Isolate untouched cell subsets from whole blood during your standard density gradient centrifugation step.
  • Choose from a wide range of RosetteSep™ reagents to isolate the cell subset of your interest.
  • Obtain highly purified, unlabeled and viable cells that are immediately ready for downstream analysis.
  • Combine RosetteSep™ with SepMate™ to minimize variability between separations.

RosetteSep™ for Human Cells


Typical Sample Source:

Whole Blood or Bone Marrow

Protocol Time:

As Little As 25 Minutes

Selection Method:

Negative Selection

Related Products

  • Density media: See table below
  • Tubes: SepMate™


  • Column-free
  • Cells are purified during standard density gradient centrifugation
  • Untouched cells are immediately ready for downstream analysis
  • Can be combined with SepMate™

Density Gradient Media



1.077 g/mL

For Enrichment of

Mononuclear Cells (MNCs)

Typical Sample Sourece

Peripheral Whole Blood, Cord Blood, Bone Marrow

Cost-effective Alternative to Ficoll® Compatible with

RosetteSep™ DM-M Density Medium


1.085 g/mL

For Enrichment of

Human Myeloid Cells

Typical Sample Sourece

Peripheral Whole Blood

Recommended for

Isolation using the following RosetteSep™ cocktail:

HLA Myeloid Cell Enrichment Kit (Catalog #15272HLA)

Use with SepMate™
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Key Applications

Cell Isolation Directly From Whole Blood

The NK Cell Cytoxicity Case Study discusses a publication from Dr. Ajay Jain’s lab at the University of Maryland School of Medicine, which used the RosetteSep™ and SepMate™ system to reduce NK cell isolation time from four hours to a single hour for a 450 mL unit of blood.

The Typical RosetteSep™ Protocol

  1. Add RosetteSep™ Enrichment Cocktail to whole blood and incubate for 20 minutes (10 minutes if using SepMate™). Dilute sample with an equal volume of PBS + 2% FBS and mix gently.
  2. Layer the diluted sample on top of the density medium. Use SepMate™ to prevent the layers from mixing.
  3. Centrifuge for 20 minutes at 1200 x g at room temperature, with the brake off. Use SepMate™ to reduce centrifugation time to 10 minutes with the brake on.
  4. Remove the enriched cells from the density medium : plasma interface.Wash enriched cells with PBS + 2% FBS. Repeat.


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