RosetteSep™ Immunodensity Cell Isolation and Cell Separation

Isolate Cells from Whole Blood During Density Gradient Centrifugation

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 (e.g. peripheral blood mononuclear cell (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.

How Does RosetteSep™ Work?

  • Unwanted cells are crosslinked to RBCs by specific antibodies forming dense immunorosettes.
  • Immunorosettes pellet during density gradient centrifugation, 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.

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 (e.g. Lymphoprep™, Ficoll-Paque™) 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.

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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™ PBMC isolation tubes to minimize variability between separations.

RosetteSep™ for Human Cell Isolation



Typical Sample Source:

Whole Blood* or Bone Marrow

Protocol Time:

As Little As 25 Minutes

Selection Method:

Negative Selection

Related Products


  • 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 Source

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 Source

Recommended for

Isolation using the following RosetteSep™ cocktail:

HLA Myeloid Cell Enrichment Kit (Catalog #15272HLA)

Use with SepMate™
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*Certain products are only available in select territories. Please contact your local Sales representative or the Product & Scientific Support team at for further information.

The Typical RosetteSep™ Cell Enrichment Protocol

The Typical RosetteSep™ Cell Enrichment 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.

Combine RosetteSep™ with SepMate™ for One-Step Cell Isolation

RosetteSep™ is easily combined with SepMate™ PBMC isolation tubes to increase sample throughput and eliminate user errors associated with improper sample layering or PBMC harvesting. This approach allows users with minimal training to consistently perform cell isolation by density gradient centrifugation and is an ideal fit for a busy laboratory environment.

Learn more about SepMate™ >

Key Applications

Cell Isolation Directly From Whole Blood

The NK Cell Cytotoxicity 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.

Antibody Finder Tool

Use our Antibody Finder Tool to ensure consistent downstream cell analysis. Find antibodies that are verified to work with RosetteSep™ products in specific applications.

Find the Right Antibody for Your Applications

Don't waste valuable research time finding the appropriate antibody for your cell analysis. Use our Antibody Finder Tool to select high-quality primary and secondary antibodies verified to work with RosetteSep™ products in specific applications.

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Related Resources

Overview of Cell Separation

Overview of Cell Separation

Learn everything you need to know about cell separation.

Read Now >

Isolate Cells from Blood

Isolate Cells from Blood

Learn about various methods to isolate different cell populations from blood samples.

Learn More >

Selected References Using RosetteSep™

See publications using RosetteSep™ >
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