Anti-GFAP antibody ValidAbTM

(HB8001)
Technical documents: SDS Datasheet

Product overview

Name Anti-GFAP antibody ValidAbTM
Host Rabbit
Clonality Polyclonal
Target GFAP
Description

Antibody to GFAP - cytoskeletal protein used as an astrocyte marker. Part of the ValidAb™ range of highly validated, data-rich antibodies.

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Validation data

Figure 1. Astrocytes stained for GFAP with HB8001 in the cerebellum.

Rat cerebellum stained by HB8001 for GFAP. Method: Rat brains were dissected and fixed overnight in 4% PFA before then being incubated in 30% sucrose (in PBS) until sunk (approx. 48hrs). A freezing microtome was used to cut 40µm horizontal slices before sections were incubated in 1% NaBH4 for 30 minutes. Sections were blocked in 0.05M glycine, 2% BSA and 3% donkey serum before incubation overnight in HB8001 (1:1000 dilution). This was followed by a two hour incubation with polyclonal goat anti-rabbit DyLight 594, Thermofisher 35561 secondary antibody. DAPI (HB0747) was used at 1µg/ml to visualise cell nuclei. For more detail please see our IHC(IF) protocol. Images were captured using a Leica DMI6000B inverted epifluorescence microscope connected to a Photometric Prime 95B camera. The image was captured as a tilescan using a 20x objective (DAPI: 106.6ms, Y3: 146.7ms exposures) in a z-stack (2.4µm spacing). The image was deconvolved in Huygens professional software before the stack was flattened using a maximum Z projection in ImageJ (Schindelin et al., 2012. Nat Methods, 9(7), 676–682).

Figure 2. Independent antibody validation of HB6406 and HB8001 in a cultured rat neuron preparation.

HB6406 and HB8001 staining completely overlaps in a cultured neuron preparation therefore showing strong evidence for specificity. Method: neurones were cultured from E17-E18 rat embryos following established protocols (Martin and Henley, 2004. EMBO, 4749–4759) and fixed with 4% PFA on DIV21. Cells were permeabilised with 0.1% Triton X-100 followed by blocking in 1% BSA, 300mM glycine. HB6406 (chicken polyclonal anti-GFAP) was incubated overnight (4°C) at a 1:2,000 dilution with HB8001 (rabbit polyclonal anti-GFAP) at a 1:2,000 dilution. This was followed by a one hour incubation with secondary antibodies (Polyclonal donkey anti-chicken Alexa Fluor 488 conjugated, Thermofisher A78948, 1:300 dilution and polyclonal goat anti-rabbit DyLight 550 conjugated, Thermofisher SA510033, 1:300 dilution). DAPI (HB0747) was used at 1µg/ml to visualise cell nuclei. For more detail please see our ICC protocol. Images were captured using a Leica SP8 AOBS confocal laser scanning microscope attached to a Leica DM I8 inverted epifluorescence microscope. The image was captured as a tilescan in Lightning deconvolution mode using a 40x objective (2.25x zoom), 405nm (21.1% power, PMT: 512V gain), 488nm (0.05% power, Hyd: 10% gain) and 561nm (0.1% power, Hyd: 10% gain) laser lines in a z-stack (0.39µm spacing). The stack was flattened using a maximum Z projection in ImageJ (Schindelin et al., 2012. Nat Methods, 9(7), 676–682).

Figure 3. Astrocyte populations in culture stained by HB8001.

HB8001 stains the populations of glia found in a cultured rat neuron preparation. Method: neurones were cultured from E17-E18 rat embryos following established protocols (Martin and Henley, 2004. EMBO, 4749–4759) and fixed with 4% PFA on DIV21. Cells were permeabilized with 0.1% Triton X-100 followed by blocking in 1% BSA, 300mM glycine. HB8001 was incubated overnight (4°C) at a 1:2,000 dilution. This was followed by a one hour incubation with secondary antibody (Polyclonal goat anti-rabbit DyLight 550 conjugated, Thermofisher SA510033, 1:300 dilution). DAPI (HB0747) was used at 1µg/ml to visualize cell nuclei. For more detail please see our ICC protocol. Images were captured using a Leica DMI6000B inverted epifluorescence microscope connected to a Photometric Prime 95B camera. The image was captured using a 20x objective (DAPI: 17.0ms, RHO, 24.5ms exposures) in a z-stack (0.6µm spacing). The image was deconvolved in Huygens professional software before the stack was flattened using a maximum Z projection in ImageJ (Schindelin et al., 2012. Nat Methods, 9(7), 676–682).

Figure 4. Concentration response of HB8001 staining in rat cerebellum.

HB8001 produces strong staining of astrocytes in rat cerebellum at dilutions as low at 1:8,000. Method: Rat brains were dissected and fixed overnight in 4% PFA before then being incubated in 30% sucrose (in PBS) until sunk (approx. 48hrs). A freezing microtome was used to cut 40µm horizontal slices before sections were incubated in 1% NaBH4 for 30 minutes. Sections were blocked in 0.05M glycine, 2% BSA and 3% donkey serum before incubation overnight in HB8001 dilutions ranging from 1:1,000 to 1:8,000. This was followed by a two hour incubation with polyclonal goat anti-rabbit DyLight 594, Thermofisher 35561 secondary antibody. DAPI (HB0747) was used at 1µg/ml to visualize cell nuclei. For more detail please see our IHC(IF) protocol. Images were captured using a Leica DMI6000B inverted epifluorescence microscope connected to a Photometric Prime 95B camera as a z-stack with a 20x objective before being deconvolved in Huygens professional software and flattened using a maximum Z projection in ImageJ (Schindelin et al., 2012. Nat Methods, 9(7), 676–682).

Exposure times were as follows:

  • 1:1,000: DAPI: 106.7ms, Y3: 146.7ms
  • 1:2,000: DAPI: 106.6ms, Y3: 161.7ms
  • 1:4,000: DAPI: 106.6ms, Y3: 285.4ms
  • 1:8,000: DAPI: 80.0ms, Y3: 395.8ms


Figure 5. GFAP expression in various tissue lysates and preparations.

HB8001 revealed the ≈55kDa band associated with GFAP only in neural tissue samples. Method: mouse brain and rat brain membrane (P2) and cytosol fractions were prepared following previous work (Molnar et al., 1993. Neuroscience 53:307-326) from freshly collected adult brains. Other tissue lysates were prepared following established protocols from freshly dissected tissue (see our guide on WB sample preparation). Samples were loaded (20µg / lane) onto a 12% acrylamide gel alongside a protein ladder (NEB Prestained protein standard, P7718S) before being run at 60V for 30 minutes followed by 130V for 100 minutes. Wet transfer to a PVDF membrane was completed in 90 minutes using 400mA. The membrane was blocked for 2hrs in 5% non-fat dry milk before being incubated overnight at 4°C in HB8001 at a 1:32,000 dilution. Following washing, the membrane was incubated in secondary antibody (1:10,000 dilution, Polyclonal goat anti-rabbit HRP conjugated, Sigma, A6154) for 2hrs. For more detail please see our Western blotting protocol. Detection was accomplished using Clarity Western ECL substrate (BioRad, 1705061) and a Licor Odyssey Fc imaging system (ECL channel: 6 min exposure, 700nm channel: 30 sec exposure). Following imaging the membrane was stripped with two changes of stripping buffer (HB7756) before being washed, blocked for 2 hours in 5% non-fat dry milk and incubated in HB9177 (mouse monoclonal anti-GAPDH, 1:4,000 dilution, 0.25µg/ml) overnight at 4°C. Following washing the membrane was incubated in a 1:10,000 dilution of a polyclonal goat anti-mouse HRP conjugated secondary antibody (Sigma Aldrich A3682) for 2hrs and visualized again using Clarity Western ECL substrate (BioRad, 1705061) and a Licor Odyssey Fc imaging system (ECL channel: 4 min exposure, 700nm channel: 30 sec exposure).

Figure 6. Concentration response of HB8001 staining in a rat brain cytosol preparation.

HB8001 shows strong affinity for GFAP with bands visible at as low as a 1 in 64,000 dilution. Method: cytosol fractions were prepared from fresh rat brains following established protocols (Molnar et al., 1993. Neuroscience 53:307-326). Rat cytosol samples were loaded (20µg / lane) onto a 12% acrylamide gel alongside a protein ladder (NEB Prestained protein standard, P7718S) before being run at 60V for 30 minutes followed by 120V for 100 minutes. Wet transfer to a PVDF membrane was completed in 80 minutes using 400mA. Following transfer the membrane was cut into strips using Ponceau dye to visualise and cut individual lanes. Strips were blocked for 2hrs in 5% non-fat dry milk before being incubated overnight at 4°C in HB8001. Each strip was incubated separately with a separate HB8001 concentration with this ranging from 1:1000 to 1:128,000 dilutions. Following washing, the membrane was incubated in secondary antibody (1:10,000 dilution, polyclonal goat anti-mouse HRP conjugated secondary antibody, Sigma Aldrich A3682) for 2hrs. For more detail please see our Western blotting protocol. Detection was accomplished using Clarity Western ECL substrate (BioRad, 1705061) and a Licor Odyssey Fc imaging system (ECL channel: 8 min exposure, 700nm channel: 30 sec exposure). Band intensity was calculated using Image Studio version 5.2.5 (LiCor) and a graph was constructed in GraphPad Prism 9 using a 3-parameter Hill equation curve fit.

Figure 7. Independent antibody validation of HB8001 and HB6406 in rat cerebellum.

The pattern of staining for HB8001 and HB6406 in the cerebellum overlaps giving strong evidence for specificity. Method: Rat brains were dissected and fixed overnight in 4% PFA before then being incubated in 30% sucrose (in PBS) until sunk (approx. 48hrs). A freezing microtome was used to cut 40µm horizontal slices before sections were incubated in 1% NaBH4 for 30 minutes. Sections were blocked in 0.05M glycine, 2% BSA and 3% donkey serum before HB8001 was incubated overnight (4°C) at a 1:2,000 dilution with HB6406 also at a 1:2,000 dilution. This was followed by a two hour incubation with secondary antibodies (Polyclonal goat anti-rabbit DyLight 594 conjugated, Thermofisher 35561, 1:300 dilution and polyclonal donkey anti-chicken Alexa Fluor 488, Thermofisher A78948, 1:300 dilution). DAPI (HB0747) was used at 1µg/ml to visualise cell nuclei. For more detail please see our IHC(IF) protocol. Images were captured using a Leica DMI6000B inverted epifluorescence microscope connected to a Photometric Prime 95B camera. The image was captured as a tilescan using a 40x objective (DAPI: 32.2ms, GFP: 133.6ms, Y3: 132.4ms exposures) in a z-stack (1.0µm spacing). The image was deconvolved in Huygens professional software before the stack was flattened using a maximum Z projection in ImageJ (Schindelin et al., 2012. Nat Methods, 9(7), 676–682).

Product information

Immunogen

Recombinant human GFAP (isoform 1) expressed in and purified from E. coli

Purification

Unpurified

Formulation Lyophilised. When reconstituted contains serum with 1% recombinant BSA and 5mM sodium azide
Predicted species reactivity Mouse, Rat, Human, Pig, Horse, Cow
Tested species reactivity Mouse, Rat

Tested applications

Applications ICC, WB, IHC(IF)
Western blot optimal concentration

1:32,000 dilution as tested in a rat brain cytosol preparation.

IHC(IF) optimal concentration

1:4,000 dilution as tested in free-floating paraformaldehyde fixed rat brain sections

ICC optimal concentration

1:2,000 dilution as tested in cultured rat neurons.

Positive control

GFAP is highly expressed in neural tissues containing astrocytes. It is not widely expressed in cell lines, however it is in specific lines such as U-87 MG.

Negative control

Most non-neural tissues.
Please note that GFAP expression has been reported in a subset of pancreatic and hepatic cells in rats and mice kidney cells. It is generally poorly expressed in common cell lines such as HeLa or HEK293.

Open data link

Please follow this link to OSF.

Target information

UniProt ID P14136
Structure image  Chemical Structure
Gene name GFAP
NCBI full gene name glial fibrillary acidic protein
Entrez gene ID

2670

Amino acids

432 (49.9kDa)

Isoforms

GFAP has three confirmed and 21 potential isoforms. Isoform 1 (GFAP alpha): canonical, 49.9kDa; Isoform 2 (GFAP epsilon): amino acid changes between positions 391 and 432, 49.5kDa; Isoform 3 (GFAP kappa): amino acid changes between positions 391 and 432, 50.3kDa

Expression

GFAP is primarily expressed within astrocytes of the central nervous system alongside also expressing in non-myelinating Schwann cells of the peripheral nervous system and satellite cells of the peripheral ganglia. GFAP expression has also been reported in Leydig cells of the testis alongside stellate cells from the pancreas and liver in rats.

Subcellular expression

GFAP is a key cytoskeletal component therefore is widely expressed as bundles of GFAP positive fibres.

Processing

Following translation, no processing is required for GFAP to reach its active conformation.

Post translational modifications

GFAP is subjected to numerous post-translational modifications including 9 phosphorylation sites which are the target of AURKB and ROCK1 alongside 5 separate citrullination sites.

Homology (compared to human)

Rat, mouse and human GFAP proteins have a 90% similarity score in a direct BLAST comparison.

Similar proteins

Other type III intermediate filament proteins have homology with GFAP including Vimentin (58%), Desmin (59%) and Peripherin (56%) when assessed using BLAST.

Storage & Handling

Storage instructions

-20°C then use reconstitution advice

Handling

Upon receipt store at either -20°C or -80°C. When ready to use there are three options:

 

  • Reconstitute with 100μl dH2O and store at 4°C
  • Reconstitue with 50μl dH2O and 50μl glycerol then store at -20°C
  • Reconstitue with 100μl dH2O, aliquot then snap freeze and store at -80°C

 

For more information read our guide on the best care for your product. Take care when opening as the precipitate is extremely light and can easily be lost if disturbed. When reconstituting make sure that the antibody is thoroughly dissolved by pipetting up and down before giving the antibody a brief spin at 10,000g to make sure that all material is recovered and at the bottom of the tube.

Important This product is for RESEARCH USE ONLY and is not intended for therapeutic or diagnostic use. Not for human or veterinary use

FAQs

What mounting media do you recommend to use with this antibody?
What guarantee do you have that my GFAP antibody will perform as expected?

We guarantee that your GFAP antibody will work for the applications and species we list on the datasheet. If the antibody fails to perform as expected then we are happy to offer a 100% refund guarantee. For more details please see our guarantee policy.

Will my GFAP antibody work against species that have not been listed on the datasheet?

A species not being listed doesn’t mean that the GFAP antibody won’t work, just that we haven’t tested it. If you test one of our antibodies in a new species please let us know (positive or negative)!

What protocols are available for use with this GFAP antibody

We have made a comprehensive collection of protocols that we have used in our experiments to validate this GFAP antibody.

Any other questions?

For any other questions about our antibody products please see our technical FAQs for antibodies

References for Anti-GFAP antibody ValidAbTM

References are publications that support the biological activity of the product
  • The role of GFAP and vimentin in learning and memory.

    Wilhelmsson U et al (2019) Biological chemistry 400 : 1147-1156
  • Importance of GFAP isoform-specific analyses in astrocytoma.

    van Bodegraven EJ et al (2019) Glia 67 : 1417-1433
  • GFAP-expressing progenitors are the principal source of constitutive neurogenesis in adult mouse forebrain.

    Garcia AD et al (2004) Nature neuroscience 7 : 1233-41
  • Glial fibrillary acidic protein: GFAP-thirty-one years (1969-2000).

    Eng LF et al (2000) Neurochemical research 25 : 1439-51
  • GFAP and astrogliosis.

    Eng LF et al (1994) Brain pathology (Zurich, Switzerland) 4 : 229-37