• Product name

    Human alpha 1 Antitrypsin ELISA Kit (SERPINA1)
    See all alpha 1 Antitrypsin kits
  • Detection method

  • Precision

    Sample n Mean SD CV%
    Overall 7.6%
    Sample n Mean SD CV%
    Overall 9.9%
  • Sample type

    Cell culture supernatant, Saliva, Milk, Urine, Serum, Plasma, Cell culture media, Cerebral Spinal Fluid
  • Assay type

    Sandwich (quantitative)
  • Sensitivity

    = 0.53 ng/ml
  • Range

    1.5 ng/ml - 10 ng/ml
  • Recovery

    103 %

  • Assay time

    4h 00m
  • Assay duration

    Multiple steps standard assay
  • Species reactivity

    Reacts with: Human
  • Product overview

    Human alpha 1 Antitrypsin  ELISA kit (SERPINA1) (ab108799) is designed for the quantitative measurement of alpha 1 Antitrypsin in urine, milk, saliva, CSF, cell lysate and cell culture supernatants.

    An alpha 1 antitrypsin specific antibody has been precoated onto 96-well plates and blocked. Standards or test samples are added to the wells and subsequently an alpha 1 antitrypsin specific biotinylated detection antibody is added and then followed by washing with wash buffer. Avidin-Biotin-Peroxidase Complex is added and unbound conjugates are washed away with wash buffer. TMB is then used to visualize HRP enzymatic reaction. TMB is catalyzed by HRP to produce a blue color product that changes into yellow after adding acidic stop solution. The density of yellow coloration is directly proportional to the amount of alpha 1 antitrypsin captured in plate.

    Get results in 90 minutes with Human alpha 1 Antitrypsin ELISA Kit (SERPINA1) (ab189579) from our SimpleStep ELISA® range.

    The entire kit may be stored at -20°C for long term storage before reconstitution - Avoid repeated freeze-thaw cycles.

  • Tested applications

    Suitable for: Sandwich ELISAmore details
  • Platform



  • Storage instructions

    Store at -20°C. Please refer to protocols.
  • Components 1 x 96 tests
    100X Streptavidin-Peroxidase Conjugate 1 x 80µl
    10X Diluent N Concentrate 1 x 30ml
    20X Wash Buffer Concentrate 2 x 30ml
    50X Biotinylated Human alpha 1 Antitrypsin Antibody 1 x 120µl
    alpha 1 Antitrypsin Microplate (12 x 8 well strips) 1 unit
    alpha 1 Antitrypsin Standard 1 vial
    Chromogen Substrate 1 x 8ml
    Sealing Tapes 3 units
    Stop Solution 1 x 12ml
  • Research areas

  • Function

    Inhibitor of serine proteases. Its primary target is elastase, but it also has a moderate affinity for plasmin and thrombin. Irreversibly inhibits trypsin, chymotrypsin and plasminogen activator. The aberrant form inhibits insulin-induced NO synthesis in platelets, decreases coagulation time and has proteolytic activity against insulin and plasmin.
    Short peptide from AAT: reversible chymotrypsin inhibitor. It also inhibits elastase, but not trypsin. Its major physiological function is the protection of the lower respiratory tract against proteolytic destruction by human leukocyte elastase (HLE).
  • Tissue specificity

    Ubiquitous. Expressed in leukocytes and plasma.
  • Involvement in disease

    Alpha-1-antitrypsin deficiency
  • Sequence similarities

    Belongs to the serpin family.
  • Domain

    The reactive center loop (RCL) extends out from the body of the protein and directs binding to the target protease. The protease cleaves the serpin at the reactive site within the RCL, establishing a covalent linkage between the carboxyl group of the serpin reactive site and the serine hydroxyl of the protease. The resulting inactive serpin-protease complex is highly stable.
  • Post-translational

    N-glycosylated. Differential glycosylation produces a number of isoforms. N-linked glycan at Asn-107 is alternatively di-antennary, tri-antennary or tetra-antennary. The glycan at Asn-70 is di-antennary with trace amounts of tri-antennary. Glycan at Asn-271 is exclusively di-antennary. Structure of glycans at Asn-70 and Asn-271 is Hex5HexNAc4. The structure of the antennae is Neu5Ac(alpha1-6)Gal(beta1-4)GlcNAc attached to the core structure Man(alpha1-6)[Man(alpha1-3)]Man(beta1-4)GlcNAc(beta1-4)GlcNAc. Some antennae are fucosylated, which forms a Lewis-X determinant.
    Proteolytic processing may yield the truncated form that ranges from Asp-30 to Lys-418.
  • Cellular localization

    Secreted. Endoplasmic reticulum. The S and Z allele are not secreted effectively and accumulate intracellularly in the endoplasmic reticulum and Secreted, extracellular space, extracellular matrix.
  • Information by UniProt
  • Alternative names

    • A1A
    • A1AT
    • A1AT_HUMAN
    • AAT
    • Alpha 1 antiproteinase
    • Alpha 1 antitrypsin
    • Alpha 1 antitrypsin null
    • Alpha 1 protease inhibitor
    • Alpha-1 protease inhibitor
    • Alpha-1-antiproteinase
    • alpha1 proteinase inhibitor
    • Alpha1AT
    • Dom1
    • PI
    • PI1
    • PRO0684
    • PRO2275
    • Serine (or cysteine) proteinase inhibitor clade A member 1
    • Serine protease inhibitor 1-1
    • Serine protease inhibitor A1a
    • Serpin A1
    • Serpin A1a
    • Serpin peptidase inhibitor clade A member 1
    • Serpina1
    • Short peptide from AAT
    • SPAAT
    • Spi1-1
    see all
  • Database links

Associated products


Our Abpromise guarantee covers the use of ab108799 in the following tested applications.

The application notes include recommended starting dilutions; optimal dilutions/concentrations should be determined by the end user.

Application Abreviews Notes
Sandwich ELISA Use at an assay dependent concentration.


  • Linearity: alpha 1 antitrypsin in urine at different diutions, corrected for the factor of dilution (duplicates +/- SD).

  • Linearity: alpha 1 antitrypsin in human milk at different diutions, corrected for the factor of dilution (duplicates +/- SD)

  • Linearity: alpha 1 antitrypsin in serum and plasma (Li-heparine) at different diutions, corrected for the factor of dilution (duplicates +/- SD)

  • Alpha 1 antitrypsin in human biological fluids (duplicates +/- SD).

    The samples were tested in different ranges of dilutions (serum and Li-heparine plasma: 2e3-1e6; CSF: 5e3-5e4; milk: 1e2-1e3; saliva: 2e2-2e3).

  • Standard curve with background signal subtracted (duplicates; +/- SD).

  • Representative Standard Curve using ab108799



This product has been referenced in:

  • Kim WS  et al. Altered High Density Lipoprotein Composition in Behavioral Variant Frontotemporal Dementia. Front Neurosci 12:847 (2018). Read more (PubMed: 30487733) »
  • Niu R  et al. iTRAQ-Based Proteomics Reveals Novel Biomarkers for Idiopathic Pulmonary Fibrosis. PLoS One 12:e0170741 (2017). ELISA ; Human . Read more (PubMed: 28122020) »
See all 12 Publications for this product

Customer reviews and Q&As

1-10 of 10 Abreviews or Q&A

I tested Human alpha 1 Antitrypsin ELISA Kit (SERPINA1) (ab108799) with Tear samples.
I performed the standard curve in duplicate while I tested the tears samples in single wells, in order to repeat the test in case of incorrect dilution of my tears samples.
I diluted tears from healthy people 1:200 and 1:400 and these dilution fell in the STD curve range, with the exception of the S3 sample, that had an OD higher than 100 ng/ml STD curve point.

RESULTS: The assay is able to detect A1AT in human tears.

CONSIDERATIONS: Let me point out that the O.D. of standard curve I obtained was quite low. Indeed,the STD curve higher point (100 ng/ml) was 0.901 OD, that is not an optimal result, considering that the absorbance reader can catch till 3.000 OD. Thus, I consider this standard curve result low for a commercial kit.
In addition, based on standard curve OD, the kit was not able to detect the 0.35 ng/ml STD curve point (that is the sensitivity declared by this kit.
Overall, the kit is able to dose A1AT in human tears.

Claudia Casnici

Verified customer

Submitted May 30 2019


Thank you for contacting us.

ab108798 is for plasma and serum samples.

ab108799 is for urine, milk, saliva and cell culture samples

Unfortunately, neither of them has cross-reactivity with mouse

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.


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Thank you for contacting us.

You can use ab108799 for serum, you will just have to optimize the dilutions to get on the standard curve. Our serum samples were at 6000X.

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.


Do you wish running an ELISA was fast and easy? Check out our new SimpleStep™ ELISA, a single wash, colorimetric sandwich ELISA assay.

Discover more at www.abcam.com/simplestep

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Thank you for your message.

I can confirm that all three of the Alpha 1 anti trypsin proteins in our catalog are from human, and are full length. Therefore, theoretically, they could be detected by the antibodies in the kit and be used for your experiments. However, please note they have not been tested in ELISA or with this kit, so regrettably we are not able to guarantee them for this purpose.

ab91136 alpha 1 Antitrypsin protein (Active)
Tested applications: SDS-PAGE, WB, FuncS
https://www.abcam.com/index.html?datasheet=91136 (or use the following: https://www.abcam.com/index.html?datasheet=91136).

ab77937 alpha 1 Antitrypsin protein (Human)
Tested applications: SDS-PAGE
https://www.abcam.com/index.html?datasheet=77937 (or use the following: https://www.abcam.com/index.html?datasheet=77937).

ab79181 alpha 1 Antitrypsin protein (Human)
Tested applications: SDS-PAGE
https://www.abcam.com/index.html?datasheet=79181 (or use the following: https://www.abcam.com/index.html?datasheet=79181).

I am sorry we have no data to confirm these would work in this case. However, I hope this will be helpful to you. If you have any further questions, please do not hesitate to contact me.

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Thank you for contacting Abcam and I do apologize for the long delay in providing you with this information.

The standard is a purified protein from human source. The assay should work for cell culture over express alpha1 antitripsin. Both native and recombinant protein should work in this assay unless the recombinant protein is a mutant.

If there is anything else I can help you with, please let me know.

Read More


Thank you for contacting us. The standard provided should only be 100 ng/ml after reconstitution. At that concentration, the recommended curve is a 1:4 dilution providing points: 25, 6.25, 1.56, and 0.391 ng/ml. Concentrations above 100 ng/ml are dangerous to calculate from as the antibody on the plate becomes saturated.

Running a 1:2 dilution of this standard, gives OD's that are very close together, and sometimes makes it difficult to produce a suitable curve. It may help to calculate your standard curve from the 25, 6.25, 1.56, and 0.391 ng/ml points in your data.

I hope this helps, please let me know if you need any additional information or assistance.

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Thank you very much for your reply.

We haven't done any studies to determine the heterogeneity of the detection antibody reagent and I don't know of amethod to really predict that accurately as it's quite complex, but Iassumethere would be ballpark 10-50 different binding sites. I'm basing this mostly on the length of the protein (418 amino acids) and size of an epitope (5-6 amino acids), which would give at least 70possibilities in one linear sequence; butof coursethe actual non-denatured native immunogen and antibodyaffinitytendenciesare more complicated, and to be on the safe side I would assume less than this number.

I hope that this will be helpful! Please let me know if you have any other questions, and have a nice day.

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Thank you very much for your reply.

Since the kits haven't been tested with non-glycosylated forms of alpha 1 antitrypsin, we don't have any data in this regard and can't say for sure. Since the antibodies used in the kit are polyclonal and raised again the full protein, they will have a range of binding sites along the length of the protein. According to the UniProt entry for this protein, there are 3 known glycosylation sites so there are still many possible antibody binding sites that are common to both glycosylated and non-glycosylated forms. There may be some bias against the non-glycosylated protein, but it's difficult to predict the extent of the bias without more data.

I am sorry that I don't have more information in this regard, but I hope this will be useful. If you have further questions or need anything else, please let me know and I'll be happy to help.

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Thank you very much for your call earlier this month and for your patience while I have been working with the lab to get this information for you. I sincerely apologize for the extended delay.

The standard is a native protein isolated from human plasma. It is greater than 95% pure by SDS-PAGE and protein assays. The antibodies were raised against this native, glycosylated protein, so the kit does work with glycosylated samples. The kit is guaranteed to work with cell culture supernatants, urine, milk, and saliva. Both the capture and detection antibodies are polyclonal.

I hope that this information will be useful, and I apologize again for the long dely. Please let me know if you have any further questions or if there is anything else that we can do for you.

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Thank you for contacting us.

Unfortunately we have not tested this kit with Plasma samples however keeping in mind the recommended sample type, it is more likely that this kit will be suitable for plasma samples also.

As we have not tested plasma sample so we will not be able to recommend the dilution to use. In similar types of kits we recommend our customer trying several serial dilutions for optimal results and the dilution factor has to be determined by end user.

I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.

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