FIX&PERM® Cell Fixation and Permeabilization Kits for Intracellular Flow Cytometry

The Industry-Standard Two-Reagent Kit for Intracellular Staining in Flow Cytometry

FIX&PERM® is a simple, two-step cell preparation kit that opens the cytoplasm and nucleus to fluorochrome-labeled antibodies — without compromising the surface markers or scatter characteristics that flow cytometry depends on. Reagent A gently fixes cells. Reagent B permeabilizes them. Together they make intracellular antigens, cytokines, oncoproteins, and immunoglobulins accessible for staining in whole blood, bone marrow, or mononuclear cell preparations.

Originally characterized by Knapp et al. (1994) and cited in hundreds of peer-reviewed publications since, the FIX&PERM kit remains the reference method many flow cytometry labs reach for first when they need to combine surface and intracellular staining in a single workflow.

FIX&PERM is manufactured by our partner brands Nordic-MUbio and Exalpha Biologicals, a Vector Laboratories company. Vector Laboratories customers can access the full FIX&PERM family directly through Exalpha (U.S. direct customers) or through distributors carrying Nordic-MUbio products (international customers).

Why Choose FIX&PERM for Intracellular Flow Cytometry Staining?

Mild Fixation, Preserved Scatter
Mild Fixation, Preserved Scatter

Mildly fixes cells, preserving their flow cytometric scatter characteristics

Surface and Intracellular in One Run
Surface and Intracellular in One Run

Allows simultaneous characterization of both intracellular and cell surface markers

Rapid
Rapid

Whole procedure can be carried out in less than one hour, ready for immediate analysis or storage for 24 hours

Proven, Validated, and Cited
Proven, Validated, and Cited

Initially characterized in Knapp et al. in 1994, independently validated in studies such as Groeneveld et al. in 1996 and Lanza et al. in 1997, and cited in hundreds of peer-reviewed publications since

Stringent Lot-to-Lot QC
Stringent Lot-to-Lot QC

The quality of each lot is confirmed using well-defined blood samples and subsequent comparison of scatter characteristics and immunostaining patterns, ensuring consistent and reliable results each time

Stable, Solvent-Free Formulation
Stable, Solvent-Free Formulation

Our formulations do not contain volatile organic solvents, enabling storage at ambient temperature during shipment and in laboratories

Flexible
Flexible

Can be used with most monoclonal antibody conjugates, as well as our range of antibodies with optimized protocols for use with FIX&PERM

CE/IVD registered kits available for European customers in a clinical laboratory setting (contact us for further information)

FIX&PERM Protocol for Intracellular Flow Cytometry Staining

Per sample: 50 µL of whole blood, bone marrow, or mononuclear cell suspension in a 5 mL tube.

  1. Add 100 µl of Reagent A (Fixation Medium, stored and used at room temperature)
  2. Incubate for 15 minutes at room temperature
  3. Add 5 ml phosphate buffered saline and centrifuge cells for 5 minutes at 300 g
  4. Remove supernatant and add to cell pellet 100 µl Reagent B (Permeabilization Medium) and 20 µl of the appropriate monoclonal antibody conjugate
  5. Vortex at low speed for 1-2 seconds
  6. Incubate for 15 minutes at room temperature
  7. Wash cells with phosphate buffered saline as described above
  8. Remove supernatant and resuspend cells in sheath fluid for immediate analysis or resuspend cells in 0.5 ml 1.0 % formaldehyde and store at 2-8°C in the dark
  9. Analyze fixed cells within 24 hours

FIX&PERM Products

Choose the FIX&PERM format that fits your throughput and workflow. All products link to the corresponding Exalpha product page for ordering.

Catalog Code

Product Name

Product Type

GAS-002

FIX&PERM® Cell Fixation and Permeabilization Kit

Buffers and Reagents

GAS-002-1

FIX&PERM® Kit 1000

Buffers and Reagents

GAS-002A-1

FIX&PERM® Solution A (Fix)

Buffers and Reagents

GAS-002B-1

FIX&PERM® Solution B (Perm)

Buffers and Reagents

GAS-002M

FIX&PERM® Sample Kit

Buffers and Reagents

Antibodies Optimized for Use with FIX&PERM

Most monoclonal antibody conjugates can be used with FIX&PERM directly. For convenience, the following mouse anti-human PE/FITC conjugates are pre-validated for FIX&PERM workflows and ship with optimized protocols.

Antigen

Clone

Isotype

Format

Quantity

Cat. No.

CD3

UCHT1

IgG1

Purified

0.2 mg

GM-4011

CD3

UCHT1

IgG1

FITC-labeled

100 tests

GM-4012

CD3

UCHT1

IgG1

PE-labeled

100 tests

GM-4013

CD22

RFB4

IgG1

Purified

0.2 mg

GM-4051

CD22

RFB4

IgG1

FITC-labeled

100 tests

GM-4052

CD22

RFB4

IgG1

PE-labeled

100 tests

GM-4053

Lactoferrin

4C5

IgG1

Purified

0.2 mg

GM-4111

Lactoferrin

4C5

IgG1

PE-labeled

100 tests

GM-4113

Myeloperoxidase

8E6

IgG1

Purified

0.2 mg

GM-4191

Myeloperoxidase

8E6

IgG1

FITC-labeled

100 tests

GM-4192

Myeloperoxidase

8E6

IgG1

PE-labeled

100 tests

GM-4193

Lysozyme

LZ-2

IgG1

Purified

0.2 mg

GM-4131

Lysozyme

LZ-2

IgG1

FITC-labeled

100 tests

GM-4132

CD68

Ki-M7

IgG1

FITC-labeled

100 tests

GM-4152

FIX&PERM Combi Panels for Dual Immunostaining

Pre-paired FITC and PE conjugates for dual-color intracellular staining protocols using FIX&PERM.

Antigen Pair

Clone(s)

Isotype

Format

Cat. No.

Negative control IgG1 (FITC + PE)

Vl-AP

IgG1

FITC + PE

GIC-201

Lysozyme (FITC) + Lactoferrin (PE)

LZ-2 / 4C5

IgG1

FITC + PE

GIC-206

Myeloperoxidase (FITC) + Lactoferrin (PE)

8E6 / 4C5

IgG1

FITC + PE

GIC-212

Myeloperoxidase (FITC) + CD3 (PE)

8E6 / UCHT1

IgG1

FITC + PE

GIC-213

Myeloperoxidase (FITC) + CD22 (PE)

8E6 / RFB4

IgG1

FITC + PE

GIC-214