Secondary Antibodies

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Human IgD mouse monoclonal antibody, clone NI 158, FITC

Applications To identify the presence of IgD in human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as direct and indirect immunofluorescence staining of cytoplasmic IgD and cell membrane IgD.
General Recommended Dilutions:
Histochemical Use: 1/10-1/100.
Reactivities Human
Conjugation FITC

Human IgG1 (Fc specific) mouse monoclonal antibody, clone NI 132 (HP 6186), FITC

Applications To identify the presence of IgG1 in human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as ELISA, indirect immunoperoxidase staining of cytoplasmic IgG1, and immunoblotting using a peroxidase labelled monoclonal antibody against FITC.
General Recommended Dilutions:
Histochemical Use: 1/10-1/50.
ELISA: from 1/200 upwards.
Western blot: from 1/400 upwards.
Reactivities Human
Conjugation FITC

Human IgG2 (F(ab)2 specific) mouse monoclonal antibody, clone NI 6014 (HP 6014), FITC

Applications To identify the presence of IgG2 in human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as ELISA, indirect immunoperoxidase staining of cytoplasmic IgG2, and immunoblotting using a peroxidase labelled monoclonal antibody against FITC.
General Recommended Dilutions:
Histochemical Use: 1/10-1/50.
ELISA: from 1/200 upwards.
Western blot: from 1/400 upwards.
Reactivities Human
Conjugation FITC

Human IgG2 (Fc specific) mouse monoclonal antibody, clone NI 25-1 (HP 6207), FITC

Applications To identify the presence of IgG2 in Human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as ELISA, indirect immunoperoxidase staining of cytoplasmic IgG2, and immunoblotting using a peroxidase labelled monoclonal antibody against FITC.
General Recommended Dilutions:
Histochemical Use: 1/10-1/50.
ELISA: from 1/200 upwards.
Western blot: from 1/400 upwards.
Reactivities Human
Conjugation FITC

Human IgG3 (F(ab)2 specific) mouse monoclonal antibody, clone NI 330 (HP 6050), FITC

Applications To identify the presence of IgG3 in human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as ELISA, indirect Immunoperoxidase staining of cytoplasmic IgG3, and immunoblotting using a peroxidase labelled monoclonal antibody against FITC.
General Recommended Dilutions:
Histochemical Use: 1/10-1/50
ELISA: from 1/200 upwards
Western blot: from 1/400 upwards
Reactivities Human
Conjugation FITC

Human IgG4 (pFC specific) mouse monoclonal antibody, clone NI 315 (HP 6206), FITC

Applications To identify the presence of IgG4 in Human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as ELISA, indirect immunoperoxidase staining of cytoplasmic IgG4, and immunoblotting using a peroxidase labelled monoclonal antibody against FITC. 
General Recommended Dilutions:
Histochemical Use: 1/10-1/50. 
ELISA: from 1/200 upwards. 
Western blot: from 1/400 upwards.
Reactivities Human
Conjugation FITC

Human IgG (Isotype Specific) mouse monoclonal antibody, clone NI 335 and NI 343, FITC

Applications To identify the presence of IgG in human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as ELISA, indirect immunoperoxidase staining of cytoplasmic IgG, and immunoblotting using a peroxidase labelled monoclonal antibody against FITC.
General Recommended Dilutions:
Histochemical Use: 1/10-1/50
ELISA: from 1/200 upwards
Western blot: from 1/400 upwards
Reactivities Human
Conjugation FITC

Human IgM mouse monoclonal antibody, clone NI 179, FITC

Applications To identify the presence of IgM in human serum, other body fluids, cell and tissue substrates and to determine its concentration in techniques as direct and indirect Immunofluorescence staining of cytoplasmic IgM and cell membrane IgM.
General Recommended Dilutions:
Histochemical Use: 1/10-1/50
Reactivities Human
Conjugation FITC

Turkey IgG (H+L chain) goat polyclonal antibody, FITC

Applications Immunofluorescence: < / = 1 µg/10e6 cells.
ELISA.
Western blotting.
Dot- and Slot-Immunoblotting.
Immunohistochemistry.
Conjugation FITC

Human IgG (F(ab)2 specific) goat polyclonal antibody, FITC

Applications Direct staining of fixed cell and tissue substrates, to demonstrate the intracellular presence of free of Ig
bound subunits of both kappa and lambda type. The absence of the Fc domain in the conjugate ensures minimal interaction with the tissue components and cell surfaces other than the primary antibody activity.
This conjugate is primarily intended for use in cell surface membrane staining procedures, to identify and quantitate Ig on B cells, especially if interference by Fc activity is expected.
Recommended Dilutions: 1/20-1/80. 
This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Reactivities Human
Conjugation FITC

Monkey IgA + IgG + IgM (H+L chain) goat polyclonal antibody, FITC

Applications Direct immunofluorescence staining of cytoplasmic Ig of appropriately treated cell and tissue substrates; to demonstrate immunoglobulins or specific antibodies in cells and tissues; to identify circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of monkey origin in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1/20 and 1/80.
Reactivities Monkey
Conjugation FITC

Monkey IgG (H+L chain) goat polyclonal antibody, FITC

Applications To identify and measure IgG, antigen or antibody, at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of monkey origin in the middle layer of the indirect test procedure.
This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1/20 and 1/80.
Reactivities Monkey
Conjugation FITC

Monkey IgG (H+L chain) rabbit polyclonal antibody, FITC

Applications Can be used to identify and measure IgG, antigen or antibody, at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of monkey origin in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1:20 and 1:80.
Reactivities Monkey
Conjugation FITC

Canine IgA (Fc specific) goat polyclonal antibody, FITC

Applications Can be used in immunocytochemical and immunohistochemical staining of IgA at the cellular and subcellular level of appropriately treated cell and tissue substrates; to demonstrate circulating IgA antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen using a reference antibody of dog origin known to be of the IgA isotype in the middle layer of the indirect test procedure. Antisera to IgA do not discriminate between serum IgA (monomeric and dimeric) and higher molecular forms such as secretory IgA. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1/20 and 1/80, depending on the method used.
Reactivities Canine
Conjugation FITC

Canine IgG (Fc specific) goat polyclonal antibody, FITC

Applications Can be used in immunocytochemical and immunohistochemical staining of IgG at the cellular and subcellular level of appropriately treated cell and tissue substrates; to demonstrate circulating IgG antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen using a reference antibody of dog origin known to be of the IgG isotype in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1/15 and 1/60, depending on the method used.
Reactivities Canine
Conjugation FITC

Canine IgG (H+L chain) goat polyclonal antibody, FITC

Applications Can be used to identify and measure IgG, antigen or antibody, at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of dog origin in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1/20 and 1/120.
Reactivities Canine
Conjugation FITC

Canine IgM (Fc specific) goat polyclonal antibody, FITC

Applications Can be used in Immunocytochemical and Immunohistochemical staining of IgM at the cellular and subcellular level of appropriately treated cell and tissue substrates; to demonstrate circulating IgM antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen using a reference antibody of dog origin known to be of the IgM isotype in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
General Recommended Dilutions: are usually between 1/10 and 1/40, depending on the method used.
Reactivities Canine
Conjugation FITC

Mouse IgM (Fc specific) goat polyclonal antibody, FITC

Applications In direct staining of cytoplasmic IgM in fixed mouse cells and tissue substrates; to identify circulating IgM antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of mouse in the middle layer of the test procedure.
This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Working dilutions are usually between 1/20 and 1/80.
Reactivities Mouse
Conjugation FITC

Sheep IgG (H+L chain) rabbit polyclonal antibody, FITC

Applications ELISA. 
Dot blot.
Immunoblotting.
Immunocytochemistry.
Immunohistochemistry Frozen Sections.

Can be used to identify and measure IgG, antigen or antibody, at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of sheep origin in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions: 1/20-1/80.
Reactivities Sheep
Conjugation FITC

Chicken IgG / Chicken IgY (H+L chain) rabbit polyclonal antibody, FITC

Applications Suitable for Immunomicroscopy and Flow cytometry or FACS analysis as well as other antibody based fluorescent assays requiring lot-to-lot consistency.
Assay Dilutions:
FLISA: 1/10,000-1/50,000.
IF Microscopy: 1/1,000-5,000.
Conjugation FITC

FITC Conjugated Rabbit Anti-Rat IgG

Applications FC: 1:100; IF/ICC: 1:32-64; IHC: 1:32-64
Reactivities Rat IgG
Conjugation FITC

FITC Conjugated Goat Anti-human IgA

Applications FC: 1:100; IF/ICC: 1:32-64; IHC: 1:32-64
Reactivities Human IgA
Conjugation FITC

Mouse IgG2a (gamma 2a chain specific) rat monoclonal antibody, clone SB84a, FITC

Applications FLISA: 1/200-1/400. 
Flow Cytometry: ≤ 1 µg/106 cells.
Identification and enumeration of IgG2a+ cells.
Immunofluorescence Microscopy: Identification and enumeration of IgG2a+ cells.
Also used as a second step reagent for mouse IgG2a monoclonal antibodies.
Reactivities Mouse
Conjugation FITC

Rat IgG1 (gamma 1 chain specific) mouse monoclonal antibody, clone G1 1C5, FITC

Applications FLISA: 1/200-1/400.
Flow Cytometry:
  1 ≤ µg/106 cells.
Immunofluorescence Microscopy: Identification and enumeration of IgG1+ cells.
Reactivities Rat
Conjugation FITC

Human IgG (Fd region) mouse monoclonal antibody, clone HP6045, FITC

Applications ELISA (both capture and detection).
Western Blot.
Radioimmunoassay
Reactivities Human
Conjugation FITC

Mouse IgG (heavy chain) rat monoclonal antibody, clone LO-MG-7, FITC, Purified

Applications Immunoassay.
ELISA: good binding on plastic.
Immunohistochemistry on frozen sections.
Indirect Immunofluorescence.
Reactivities Mouse
Conjugation FITC

Mouse IgG2a goat polyclonal antibody, FITC

Applications Flow Cytometry: 1/10.
Immunofluorescence: 1/10.
Reactivities Mouse
Conjugation FITC

Mouse IgG2b goat polyclonal antibody, FITC

Applications Flow Cytometry: Use 10 µl of Neat-1/10 diluted antibody to label 106 cells in 100 µl.
Immunocytochemistry: Neat-1/10. 
Immunohistochemistry on Frozen Sections.
Reactivities Mouse
Conjugation FITC

Mouse IgA goat polyclonal antibody, FITC

Applications Flow Cytometry: Use 10 µl of neat-1/10 diluted antibody to label 10e6 cells in 100 µl.
Immunofluorescence: neat-1/10.
Immunohistochemistry on Frozen Sections.
Reactivities Mouse, Rat
Conjugation FITC

Human IgD (heavy chain) goat polyclonal antibody, FITC

Applications Flow Cytometry: Use 10 µl of Neat-1/10 diluted antibody to label 106 cells in 100 µl.
Immunocytochemistry: Neat-1/10.
Immunohistochemistry on Frozen Sections.
Reactivities Human
Conjugation FITC

Human IgD (F(ab)2 Fragment) goat polyclonal antibody, FITC

Applications Flow Cytometry: Use 10 µl of Neat-1/10 diluted antibody to label 10e6 cells in 100 µl.
Immunofluorescence: Neat-1/10.
Immunohistochemistry on Frozen Sections.
Reactivities Human
Conjugation FITC

Chicken IgM (Fc specific) goat polyclonal antibody, FITC

Applications Can be used in Immunocytochemical and Immunohistochemical staining of IgM at the cellular and subcellular level of appropriately treated cell and tissue substrates; to demonstrate circulating IgM antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen using a reference antibody of chicken origin known to be of the IgM isotype in the middle layer of the indirect test procedure.
This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended working dilutions: 1/10 - 1/40, depending on the method used.
Reactivities Chicken
Conjugation FITC

Rabbit IgG (H+L chain) chicken polyclonal antibody, FITC

Applications Immunocytochemistry.
Immunohistochemistry (1/250).
Quality Control: Antibodies were tested for specificity using Double-Immunodiffusion assays in agarose and for non-specific binding using Cryostat sections of unfixed embryonic chick tissues.
Reactivities Rabbit
Conjugation FITC

Mouse IgG3 goat polyclonal antibody, FITC

Applications Flow Cytometry: Use 10 µl of Neat-1/10 diluted antibody to label 106 cells in 100 µl.
Immunocytochemistry: Neat-1/10.
Immunohistochemistry on Frozen Sections.
Reactivities Mouse
Conjugation FITC

Mouse IgA+IgG+IgM (H+L chain) goat polyclonal antibody, FITC

Applications

FLISA.
Immunofluoresecence: ≤ 1 μg/106 cells.
Flow Cytometry.
Immunohistochemistry.

Reactivities Mouse
Conjugation FITC

Duck IgG (H+L chain) rabbit polyclonal antibody, FITC

Applications ELISA.
Immunocytochemistry.
(In)direct Immunofluorescence.

Immunohistochemistry on Frozen Sections.
Can be used to identify and measure IgG, antigen or antibody, at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of duck origin in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions:  1/20-1/80.
Reactivities Duck
Conjugation FITC

Guinea Pig IgG (Fc specific) sheep polyclonal antibody, FITC

Applications ELISA.
(In)direct immunofluorescence.

Immunocytochemistry.
Immunohistochemistry on Frozen Sections.
Can be  used in direct staining of cytoplasmic IgG in fixed guinea pig cells and tissue substrates; to identify circulating IgG antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of guinea pig in the middle layer of the test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions: 1/20-1/80.
Reactivities Guinea Pig
Conjugation FITC

Sheep IgG (Fc specific) rabbit polyclonal antibody, FITC

Applications ELISA. 
Immunocytochemistry.  
(In)direct Immunofluorescence.

Immunohistochemistry on Frozen Sections.
Can be used In direct staining of cytoplasmic IgG in fixed sheep cells and tissue substrates; to identify circulating IgG antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of sheep in the middle layer of the test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions1/20-1/80.
Reactivities Sheep
Conjugation FITC

Sheep IgM (Fc specific) rabbit polyclonal antibody, FITC

Applications ELISA. 
Dot blot.
Immunoblotting.
Immunocytochemistry.
Immunohistochemistry Frozen Sections.

Can be used in immunocytochemical and immunohistochemical staining for the detection of IgM at the cellular and subcellular level by staining of appropriately treated cell and tissue substrates; to demonstrate circulating IgM antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen using a reference antibody of sheep origin known to be of the IgM isotype in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions: 1/20-1/80.
Reactivities Sheep
Conjugation FITC

Sheep IgM (H+L chain) rabbit polyclonal antibody, FITC

Applications ELISA. 
Dot blot.
Immunoblotting.
Immunocytochemistry.
Immunohistochemistry Frozen Sections.

Can be used to identify IgM at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases, where IgM and IgG antibodies can be expected. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions: 1/20-1/80.
Reactivities Sheep
Conjugation FITC

Porcine IgG (H+L chain) rabbit polyclonal antibody, FITC

Applications ELISA. 
Immunocytochemistry. 
Immunofluorescence.
Immunohistochemistry Frozen Sections.

Can be used to identify and measure IgG, antigen or antibody, at the cellular and subcellular level by immunofluorescence staining of appropriately treated cell and tissue substrates, and to demonstrate circulating antibodies in serodiagnostic microbiology and autoimmune diseases; to identify a specific antigen or immune complex using a reference antibody of swine origin in the middle layer of the indirect test procedure. This immunoconjugate is not pre-diluted. The optimum working dilution of each conjugate should be established by titration before being used. Excess labelled antibody must be avoided because it may cause high unspecific background staining and interfere with the specific signal.
Recommended Working Dilutions1/20-1/80.
Reactivities Porcine
Conjugation FITC

Guinea pig IgG (H+L chain) rabbit polyclonal antibody, FITC

Applications This product is designed for immunofluorescence microscopy, fluorescence based plate assays (FLISA) and fluorescent western blotting. This product is also suitable for multiplex analysis, including multicolor imaging, utilizing various commercial platforms.
Suitable for Immunomicroscopy and Flow Cytometry or FACS analysis as well as other antibody based fluorescent assays requiring lot-to-lot consistency.
Recommended Dilutions:
FLISA: 1/10,000-1/50,000.
Flow Cytometry: 1/500-1/2,500.
IF Microscopy: 1/1,000-1/5,000.
Conjugation FITC

Guinea pig IgG (H+L chain), adsorbed goat polyclonal antibody, FITC

Applications Suitable for Immunomicroscopy and Flow cytometry or FACS analysis as well as other antibody based fluorescent assays requiring lot-to-lot consistency.
Conjugation FITC

Human IgG (gamma chain specific) rabbit polyclonal antibody, FITC

Applications Suitable for Immunomicroscopy and Flow cytometry or FACS analysis as well as other antibody based fluorescent assays requiring lot-to-lot consistency.
Conjugation FITC

Rabbit IgG (H+L chain) (Fab Fragment) goat polyclonal antibody, FITC

Applications Suitable for immunomicroscopy and flow cytometry or FACS analysis as well as other antibody based fluorescent assays requiring extremely low background levels, absence of F(c) mediated binding, lot-to-lot consistency, high titer and specificity.
Recommended dilutions:
Flow cytometry 1:2,000 - 1:10,000
Immunofluorescence 1:1,000 - 1:5,000
FLISA:1:10,000-1:50,000.
Conjugation FITC

Mouse IgM (heavy chain) rat monoclonal antibody, clone LO-MM-9, FITC

Applications Flow Cytometry: 5 µg/ml; use 5 µl of the suggested working dilution to label 10e6 cells in 100µl.
Reactivities Mouse
Conjugation FITC

Human IgG3 (Hinge Region) mouse monoclonal antibody, clone HP6050, FITC

Applications FLISA: 1/200-1/400
Immunocytochemistry.
Immunohistochemistry on Frozen Sections.
Reactivities Human
Conjugation FITC

Porcine IgA goat polyclonal antibody, FITC

Applications Flow Cytometry.
Immunohistochemistry on Frozen Sections: 1/200-1/2000.
Reactivities Porcine
Conjugation FITC

Mouse IgD (Delta heavy chain) rat monoclonal antibody, clone 11-26, FITC

Applications Flow Cytometry: < / = 1 µg/10e6 cells. (See Ref.1-5)
Immunofluorescence.
Reactivities Mouse
Conjugation FITC

Mouse IgE (Epsilon heavy chain) rat monoclonal antibody, clone 23G3, FITC

Applications Flow Cytometry: < / = 1 µg/10e6 cells.
Identification and enumeration of IgE+ cells.
Immunofluorescence Microscopy: Identification and enumeration of IgE+ cells.
Reactivities Mouse
Conjugation FITC