Below you will find some frequently asked questions. If there are any additional questions, please contact us at so we can help.


1. How does PTM ensure the quality of their antibodies?

Rigorous in-house standards validate each antibody’s high specificity and affinity. Our strict quality control standards include:

  • In-house assays with modified peptides show a detection limit as low as 4 ng.
  • Ensuring no cross-react with other modified peptide by testing the antibody for a large panel of structurally similar modified peptides using dot blot.
  • Competing with antigen peptides confirms the specificity of the antibody.
  • Treating cells with specific activators or inhibitors verifies target specificity.

2. Does PTM test all their antibodies on the species that are not listed on PTM Biolabs product datasheet?

All the pan antibodies have been tested on bacteria, yeast, drosophila, mouse, and human cells. The histone sequence specific antibodies have tested in different eukaryotic cell lines. You can contact the technical support team at for further information.

3. How does PTM ensure the consistency between lot to lot?

Each lot only released after validating the affinity and specificity by ELISA, dot blot, WB, and IP side by side with the old lot.

4. Can I specify the lot number when I place an order?

Yes, please contact for your special request. However, due to the minor difference between lot to lot of polyclonal antibodies for certain applications such as ChIP, we recommend purchasing a bulk size for the antibody that works for you.

5. Were your antibodies cited in any publications?

Our antibodies are well-cited. You can find all the publications listed on the “Publication” tab in the Media center of our website.


1. Are PTM antibodies ChIP grade?

We realize how ChIP assay is important for epigenetic research. Our current project is to test all our antibodies on the ChIP assay. Also, most of our pan antibodies have been tested on CHIP assay by the customers. Please contact technical support team at for further assistant on which antibody will perform best in ChIP assay.

2. What is the concentration of PTM antibody?

Antibody concentration is adjusted based on the optimization of client expected assays rather than amount of protein. Please contact the technical support team at for the concentration of a particular antibody. Also, we offer flexibility in pack sizes by antibody concentration per special request.

3. Can I order a carrier free antibody?

Yes, please contact the customer support team at for the availability and pricing. Also, we offer bulk sizes by antibody concentration per request.

4. Can PTM develop an antibody upon request?

Antibody development service is part of our All-In-One proteomic service package. We do not provide custom antibody in general but we like to hear your suggestions. Please contact customer support team at for your suggestions or to find out the list of new developing products.

5. Do you offer free test samples?

We do not offer free or small aliquot for testing purposes. Our policy is that if the antibody does not work on the species or applications indicated in our product datasheet, we will offer a replacement or re-credit.


1. Does my antibody work on the applications that you didn’t list in your QC datasheet?

We only recommend the applications that have passed our validation tests. If you are interested in other applications that are not listed in our product datasheet, please contact the technical support team at for further assistant on which antibody will perform best in your desired application.

2. When there are multiple choices for one antibody, which one should I choice?

PTM often provides polyclonal and monoclonal antibodies against each PTM target. Please contact technical support team at for further assistant on which antibody will perform best in your desired application.

3. Can I use my own WB protocol with PTM antibodies?

Yes. However, we recommend following the standard WB protocols which have been optimized to a strong signal with clean background listed in PTM antibody product web page.

4. Can I order the positive control peptides that you used in your quality control experiment?

We provide different sizes of cell lysate we used in our QC validation tests for your positive control experiments.

5. How do I know the band pattern is real for pan antibodies?

You can treat cells with specific activators or inhibitors to verify the target specificity.

6. What concentration should I use for WB?

You can find the optimal antibody dilution for the tested applications predetermined by our scientists in the product datasheets. However, the optimal dilutions/concentrations should be determined by the end user and use it as an assay dependent.

7. Can I use nonfat milk to block the blot instead of BSA that you stated in your protocol?

Yes, our scientists found out there are no difference of using nonfat milk or BSA as blocking solution for our antibodies.

8. Can you provide the antigen peptide for my positive control experiment?

The antigen sequence is proprietary information and we are unable to release this information.

9. I have trouble to detect any signals from WB using your pan antibody, any suggestions?

The detection of a PTM, e.g., lysine acetylation and lysine propionylation, using pan anti- PTM antibodies is technically challenging. For example, western blotting analysis of Kac is much more challenging because Kac has smaller antibody binding pocket. We will need to know more detail about your experimental procedures for troubleshooting. Please contact the technical support team at for further assisting your particular issue. Our scientists who developed and analyzed these reagents will also work with you to provide the solution that you need.

10. How do I prepare cell lysate for WB?

Our antibodies are well cited in many publications. You can check the sample preparation and WB procedures in the publications cited in the individual product datasheet. Or you can make a request at for the protocols of sample preparation, WB, and IP assays.

11. How do I store the antibody?

Antibodies should be always stored at -20°C. Freeze/thaw cycles may reduce the antibody’s binding affinity. Our antibodies are stored in glycerol to a final concentration of 50% to prevent freeze/thaw damage.



1. How do I place an order?

We accept orders via:

(1) Online: Add the products to the shopping cart and process the checkout by creating an account with us (highly recommended) .You can use a Purchase Order Number or credit card to place the order.

(2) Fax : +1 312-243-2267

(3) Email:

(4) Phone: +1-312-802-6843

2. Do you accept PO order?

Yes, you can either send your PO orders via fax (+1-312-243-2267) or email (

3. How do I check the antibody availability?

Please contact customer support at for stock availability.

4. How do I get a quote?

Please contact sales support at for your inquiries.

5. Do you accept credit card? Do you accept American Express?

You can either pay online via credit card or call us at +1312-802-6843 to provide your credit card information. We accept Master, VISA, American Express, and Discovery.

6. What are your payment options?

(1) Pay via check:
Mailing Address: 2201 W. Campbell Park Drive, Suite 305, Chicago, IL 60612
(2) Pay via Wire Transfer:
Contact or +1.312.802.6843 for more information

(3) Pay via Credit Card:

7. Can I purchase a small aliquot of your antibody for my pilot experiment?

We offer Mutliplex sets for purchase which include any 3 or 5 antibodies of your choice in 25/50 µl. Please contact sales support at for your special needs.

8. Can I get a discount?

We offer discounts for bulk size order. Please contact sales support at for custom orders. Stay tune with our latest news at for new product release and promotions.

9. Do you have a distributor in my country?

We have one distributor located in the Netherlands.
We currently do not have other distributors.
**For distribution opportunites, contact us at or +1-312-802-6843

10. How much does the shipping & Handling fee charge?

Domestic shipping: either $60 to $80 depending on region
International shipping: $180 (exclusive of VAT)
**Please contact us at info@ptm-biolabs for special requests on shipping.

11. Can I use my own shipping courier?

Yes. Please provide your shipping account number in your purchase orders or contact us at info@ptm-biolabs for your special request.

12. When do I receive the product?

All in-stock, domestic orders received Monday through Wednesday before 5 p.m. (CST) are shipped the same day and delivered in the next day.
International orders are shipped on Mondays or Fridays to avoid weekend holdover by customs clearance. The transition is about 3 to 4 business days.

13. What information do I need to provide for my order?

Please provide following information to complete your order:

  • Product catalog number and quantity desired
  • Shipping address and billing address
  • Purchase order number or credit card number
  • Your contact information (phone number and email). So we can contact you directly regarding the stock availability and shipping status.

14. Do you charge VAT?

Our price does not include VAT. For the customers outside of US, we must charge VAT unless your organization is VAT exempt. You can also provide your VAT number or your shipping account while you are placing your order.