Caspase 1 protein (Active) (ab39901)

I do understand what you are saying, but when production prepares the vials they MUST know how much that they are putting in. Is there a mass/vial or even an activity/mass associated with each lot that would allow us to figure this out. I am only being persistent because it will be imperative for me to know how much protein I am using and obviously, I cannot measure the mass of micrograms of sample.

Thank you,

ANSWER:

Thank you for your reply.

I certainly understand that the mass concentration would be imperative when using in Western blot. Unfortunately this is considered proprietary information and I cannot provide it.
I've looked through our catalog and we do not have any other human caspase 1 proteins. Iapologize for this inconvenience and that I do not have a better answer to provide.

Please let me know if you have any further questions or if there is anything else that we can do for you, and I'll be happy to help.

How many micrograms are provided per vial? This productis the active caspase 1heterotetramer comprised of small subunits (10 kDa) and large subunits (20 kDa), correct?

ANSWER:

Thank you for your call earlier this week and for your patience while I have been in touch with the producing lab about ab39901.

This protein is provided as the heterotetramer of the small (10 kDa) and large (20 kDa) subunits of caspase 1. It is not the immature protein. It is packaged as 25 units per vial, so there isn't a specific mass per vial, but it should be a few micrograms based on the activity of >5000 units/mg.

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

Our lab want to purchase caspase 1 (ab39901) and caspase 3 (ab52101) for
my project. We have one question regarding these products. We want to know
if we are going to cut our protein (40ug) with caspase 1 or 3, how many ul of
caspase 1 or 3 we need to add into the buffer in order to have a useful reaction?
Another question is I checked your website but I only found 25 units in caspase 1
and 100 units in caspase 3. Can I have the information about how many ul or ml
you have in one tube of caspase 1 or 3?
Thank you for all the information.

ANSWER:

Thank you for contacting Abcam.

For ab39901, Caspase 1, we recommend using 1 unit/assay for analyzing caspase activity and this protein has a biological activity : >5000 units/mg and it is supplied lyophilized and it should be reconstituted to 1 unit per µl in PBS containing 15% glycerol (and as it supplied as 25 units you would end up with 25ul of solution).

For ab52101, Caspase 3, one unit of the recombinant caspase-3 is the enzyme activity that cleaves 1 nmol of the caspase substrate DEVD-pNA (pNA: pnitroanaline) per hour at 37oC in a reaction solution containing 50 mM Hepes, pH 7.2, 50 mM NaCl, 0.1% Chaps, 10 mM EDTA, 5% Glycerol, and 10 mM DTT. You are supplied with 100 units and again it is lyophilized on arrival an you should reconstitute to 1 unit per µl in PBS containing 15% glycerol (therefore you would have 100ul of solution).

The above are recommended starting dilutions, however the optimal dilutions/concentrations should be determined by the end user.

Please let me know if there is anything else I can help you with.

Dear Sir/Madame, I would like to know how you define one unit of enzymatic activity for the following product: Caspase 1 protein (Active) (ab39901)

ANSWER:

Thank you for your inquiry. Please see below for the unit definition for ab39901 (Caspase 1 protein (Active)): One unit of the recombinant Caspase-1 is the enzyme activity that cleaves 1 nmol of the caspase substrate YVAD-pNA (pNA: pnitroanaline) per hour at 37C in a reaction solution containing 50 mM Hepes, pH 7.2, 50 mM NaCl, 0.1% Chaps, 10 mM EDTA, 5% Glycerol, and 10 mM DTT. Please note the different substrate to Caspase 3. I hope this information is helpful. Please do not hesitate to contact me again with any further questions.

in which step is the dilution buffer to be used? it is not mentioned in the protocol

ANSWER:

Thank you for contacting us. I have heard back from the lab with the following information: The dilution buffer can be used to dilute the caspase 1 protein (ab39901) when being used as a positive control. Thus, the protocol is correct as it is.

Could you please describe the problem you encountered as well as the type of samples you have been using? Were there any deviations from the protocol that you might have implemented? What is the order or PO number used to purchase the kit?

Please let me know this information so that I can help you further with resolvng the issues with this product. I look forward to hear back from you.