Anti-Prostate Specific Antigen antibody [PSA1] (ab403)

Dear technical team,

Our customer purchased ab78528, ab403, ab53774 and ab9785.
His major is "electrical engineering' and he is going toapply those itemssimilar sELISA method.
He would like to confirm if PBS is okay as a dilution buffer.
Check this please.

ANSWER:

Thank you for contacting us.

Indeed, I can confirm that PBS as dilution buffer is suitable for all three antibodies and the protein.

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

How was the affinity constant determined?

ANSWER:

Thank you for your enquiry.

The affinity constant was determined by RIA. In brief, according to the lab that performed this characterization:

"Dilution series of antibody ab403 has been prepared and all dilutions have been incubated with 125 I (iodine)labeled PSA antigen. Bound antibodies have been separated with PEG precipitation and counts have been measured. Amount of free antibodies has been calculated by using total max of the test run. Affinity curve has been formed from values of bound/free versus bound and then the coefficient has been calculated using slope of the curve and molecular weight of the antigen."

More detailed method descriptions can be found in the literature or on the internet. I recommend a book from the Practical Approach series: Immunoassays, edited by J. P. Gosling, from Oxford University Press, 2000.

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

I would like to know pI (isoelectric point) value for this antibody. Do you have this information?

ANSWER:

Thank you for your patience in this matter.

I have received a reply from the originator of ab403 (PSA antibody). The pI value of this product is 6,0 - 6,7. The assay method is PhastSystem, PhastGel IEF 3-9.

I hope this information is useful for you.

The affinity constant for this product is listed as 1x10^11I/mol. What are the units on I?

ANSWER:

Thank you for your enquiry. My apologies for delay, it has taken some time to confirm this information for you.

l stands for litre, and l/mol is for affinity: [AgAb]/[Ag][Ab], which gives units l/mol.

I hope this is helpful. Should you require any further assistance, please do not hesitate to contact us again.

Thanks for the reply. Unfortunately we cannot order a large amount. Do you mind give me the contact information of the antibody originator? I thought it would not be very difficult by NOT adding BSA. Second question: if it is impossible to get the above BSA-free antibody, how about the ab403 and ab2218. Do they contain BSA or any other proteins in their storage buffer?

ANSWER:

Thank you for your email. I can't tell you the name of the originator of ab9537 as that information is proprietary.

I double-checked ab403 and ab2218, and both of these do not contain BSA or other proteins in the storage buffer. Ab403 consists of preservative: 0.1% Sodium Azide, and constituents: sodium chloride, citrate / phosphate. pH 6.0. Ab2218 consists of preservative: 15mM sodium azide, and constituents: PBS. pH 7.4.

Please contact us again if you have any additional questions or concerns.