Overview

Description

  • Nature
    Native
  • Source
    Escherichia coli
  • Amino Acid Sequence
    • Species
      Escherichia coli
    • Molecular weight
      465 kDa
    • Additional sequence information
      Beta Galactosidase is a homotetramer with a molecular weight of 465.4 kDa (116.3 kDa subunits each).

Specifications

Our Abpromise guarantee covers the use of ab7981 in the following tested applications.

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

  • Biological activity

    One Unit hydrolyzes one micromole of o-nitrophenyl-β-D-galactopyranoside per minute at 25°C, pH 7.5.

    Activity: ≥50 units per mg dry weight.

    Optimum pH range of 6 to 8.

     

  • Form
    Lyophilised
  • Concentration information loading...

Preparation and Storage

  • Stability and Storage

    Shipped at 4°C. Store at +4°C.

    This product is an active protein and may elicit a biological response in vivo, handle with caution.

  • Reconstitution
    Reconstitute in 0.1 M Sodium/potassium phosphate, pH 7.0.

General Info

  • Alternative names
    • Beta D galactosidase
    • Beta gal
    • Beta galactosidase
    • ECK0341
    • JW0335
    • Lactase
    • lacZ
    see all
  • Relevance
    Beta galactosidase is coded by a gene (lac z) in the lac operon of Escherichia coli. It is a metalloenzyme that splits lactose into glucose and galactose. It hydrolyzes terminal, non-reducing beta-D-galactose residues in beta-D-galactosides. Activation by cations seems to be substrate dependent. K+, Na+, NH4+, Rb+, Cs+ and Mn++ all activate enzyme activity based upon the substrate used.
  • Cellular localization
    Cytoplasmic

References

ab7981 has not yet been referenced specifically in any publications.

Customer reviews and Q&As

1-7 of 7 Abreviews or Q&A

Answer



ab7981:

It is an active protein, the assay we use to determine activity is Beta galactosidase assay. We have not sequenced this product but it is sourced from E coli and should be similar to P00722 (http://www.uniprot.org/uniprot/P00722). It is sold as 5000 units and one unit is defined as one Unit hydrolyzes one micromole fo p-nitrophenyl-B-D-galacotpyranoside per minute at 25deg.C, pH 7.5

ab79449:

This product is native protein from Escherichia coli and a sequence is not determined. The level of enzymatic activity is not guaranteed, but the enzyme was tested for activity using 2-nitrophenyl-b-galctoside and/or 4- nitrophenyl b D-galactoside.

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Answer

Thank you for your enquiry and interest in our products.

I can confirm that these two products (ab7981 and ab79449) are not His-tagged. I have checked our catalogue and currently we only sell non-tagged beta Galactosidase protein.

If you need any further assistance in the future, please do not hesitate to contact me.

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Question
Answer

Thank you for contacting Abcam earlier today.

For lot * there are 165 u/mgDW (dry weight) in this lot.

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

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Answer

Thank you for contacting us yesterday.

I am sorry to hear you are experiencing difficulties with one of our products. As discussed over the phone, I'd like to try and help you to improve the results currently obtained. In order to do this, could you please fill out the questionnair I have attached to this email. If you could also include some images of the blots obtained that would be very helpful. I understand that you have already performed a lotof optimisation but if you could just briefly outline what you have tried to optimise that would be very helpful.

I think it would be worthwhile to try and use the beta Galactosidase protein (ab7981) which you have just to check that there is not a problem with the antibody itself thatare contributing to the poor results.

In answer to you questions in regards to how to use this protein as a control. We recommend reconstituting the protein in a minimum concentration of 1 mg/mL in 0.1 M Sodium/potassium phosphate buffer, pH 7.0. This can be performed as follows:

0.1 M Sodium phosphate buffer: Dissolve 1.42 gms sodium phosphate dibasic (MW 141.98) in reagent grade water to a final volume of 100 ml.

0.1 M Potassium phosphate buffer: Prepare by dissolving 1.36 gms potassium phosphate monobasic (MW 136.1) in reagent grade water to a final volume of 100 ml.

0.1 M Sodium/potassium phosphate, pH 7.0: Take 60 ml sodium phosphate buffer 0.1 M and adjust pH to 7.0 with 0.1 M potassium phosphate buffer. Buffer may be stored at 2 - 8°C for 2 - 3 weeks.

The lypolised powder the protein is provided as can be stored at2-8°C but once dissolved it is best to aliquot and freeze stocks at -20C or -80C. We do not have any reconstituted stability data andwould therefore recommend to reconstitute the amount needed for the assay fresh just prior to performing the assay.

I would recommend initially loading 0.1 ug in a well to see how well the antibody performs next to your samples. This value may need to be reduced if the signal observed is too strong compared to your lysates.

I hope this information has been of help. I look forward to receiving your reply.

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Question
Answer

Thank you for your call today and for your question about ab7981.

The buffer recommended for reconstitution is based on the assay described in the following reference:

Craven et al. (JBC, 240, 2468,1965)

The buffer is 0.1 M Sodium/potassium phosphate, pH 7.0.

The buffer formulation is as follows:

0.1 M Sodium phosphate buffer: Dissolve 1.42 gms sodium phosphate dibasic (MW 141.98) in reagent grade water to a final volume of 100 ml.

0.1 M Potassium phosphate buffer: Prepare by dissolving 1.36 gms potassium phosphate monobasic (MW 136.1) in reagent grade water to a final volume of 100 ml.

0.1 M Sodium/potassium phosphate, pH 7.0: Take 60 ml sodium phosphate buffer 0.1 M and adjust pH to 7.0 with 0.1 M potassium phosphate buffer. Buffer may be stored at 2 - 8°C for 2 - 3 weeks.

The lyophilized powder can be stored at 2-8C but once dissolved it is best to aliquot and freeze stocks at -20C or -80C. We do not have any reconstituted stability data and but is recommended to reconstitute the amount needed for the assay fresh just prior to assay.

I hope this information will be useful, but please let me know if you have any further questions and we'll be happy to help.

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Answer

Thank you for contacting us. The current lot we have in stock, GR20915-2, has 51.0 units activity per milligram dry weight, so you should receive 98 mg. Other lots will vary in the unit activity per milligram. We suggest reconstituting at a minimum concentration of 1 mg/ml. The buffer recommended for reconstitution is based on the assay described in the following reference: Craven et al. (JBC, 240, 2468,1965) The buffer is 0.1 M Sodium/potassium phosphate, pH 7.0. The buffer formulation is as follows: 0.1 M Sodium phosphate buffer: Dissolve 1.42 gms sodium phosphate dibasic (MW 141.98) in reagent grade water to a final volume of 100 ml. 0.1 M Potassium phosphate buffer: Prepare by dissolving 1.36 gms potassium phosphate monobasic (MW 136.1) in reagent grade water to a final volume of 100 ml. 0.1 M Sodium/potassium phosphate, pH 7.0: Take 60 ml sodium phosphate buffer 0.1 M and adjust pH to 7.0 with 0.1 M potassium phosphate buffer. Buffer may be stored at 2 - 8°C for 2 - 3 weeks. The lyophilized powder can be stored at 2-8C but once dissolved it is best to aliquot and freeze stocks at -20C or -80C. We do not have any reconstituted stability data and but is recommended to reconstitute the amount needed for the assay fresh just prior to assay. 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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Answer

Thank you for your inquiry. I am afraid that these products, ab7981 and ab79449, does not contain a His tag. If there is anything else that I can help you with, please do not hesitate to contact me.

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Please note: All products are "FOR RESEARCH USE ONLY AND ARE NOT INTENDED FOR DIAGNOSTIC OR THERAPEUTIC USE"

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