Native Human Collagen VI protein (ab7538)

I have contacted the laboratories who confirmed that the collagen is not assessed specifically for telopeptides. Lower molecular weight subunit strands are not expected in the unreduced collagen.

When the collagen has been loaded on 4-20% gradient gels, only the reduced collagen sample was observed to show bands, the non-reduced sample was too large to run on the gel.

I can confirm the collagen is present as triple helices. The size is not determined but the native protein is normally too large to run in standard 4-8% polyacrylamide gels.

Thank you for keeping me updated about the results, and also for your patience while I've been in touch with the lab that produces this protein.

I do have a couple of suggestions that will hopefuly improve the results, but I was unfortunately not able to obtain any data or images from the production lab.

I also have a couple of additional questions that might be helpful for optimization:

1)Were standard reduced, denatured conditions used in the Western blot protocol?
2) What positive control was used in WB?
3) Was a Coomassie or other gel stain done before transfer to the membrane?
4) Do you have any images that you could send to me?

Here is the ELISA protocol that is used to quantify collagen:

1) Coat the plate with unlabeled anti-collagen (type specific) at 10 ug/ml.
2) Use biotinylated anti-collagen (same specificity) at a concentration of 0.1 ug/ml.
3) Dissolve the collagen firstly in 0.5 M Sodium Acetate.
4) Dilute the collagen in 0.05 M Tris Cl, 1.0 M Sodium Chloride, pH. 7.4.
5) Perform serial dilutions of the collagen using the Tris/NaCl buffer.
6) Perform all steps at 4° C using overnight incubations.
7) All buffers are to be at 4° C.
8) Use Streptavidin-HRP for detection.

I don't have the full protocol that was used in WB, however my contact at the lab recommendsnative, non-denaturing conditions (no heat, reducing agents or SDS) in WB. Bands are most frequently reported between 80 and 120 kDa. The antibody you have was raised against the native protein so the affinity should be higher under these conditions.

With this protein, the anti-collagen VI antibodies ab6588 and ab6583 are recommended for detection, however the collagen VI antibody that you have should work as well. We do fully guarantee this protein to work as specified on the datasheet, so if you would prefer a replacement, credit, or refund, please let me know and I'll be happy to arrange this for you.

I hope that this information will be useful, and I look forward to hearing from you. Please let me know if you have further questions or if there is anything else that we can do for you.

Thank you for contacting us with your question.

The collagen VI protein Ab7538 is a native protein, and it is purified full length protein isolated from human placenta. Thus it will contain the three subunits A1, A2, and A3.

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.

Thank you for contacting Abcam regarding our Collagen VI proteins.


I have confirmed with the laboratory that both proteins on our catalog have been pepsin-treated.


I hope this information is helpful and I apologize for any inconvenience this may cause. Please do not hesitate to contact us if you have any additional questions or concerns.

Thanks for your call yesterday and for your patience while I have been in touch with the lab regarding your enquiry.

This protein has been treated by limited pepsin digestion.Bands most often appear between 80-120 kDa and vary depending on sample preparation and gel type.Collagen antibodies often have higher affinity for the non-denatured protein, so it is common to run a non-denaturing gel with this protein.

I hope this information is helpful, but please let me know if you have any further questions or if there is anything else that we can do for you.

I'm afraid I was unable to find out if this collagen was pepsinised. However, we do not recommend to use reduced conditions of SDS-PAGE for collagens and I would suggest to run a native (non-denaturing, non-dissociating) PAGE which should give you the appropriate band sizes. I hope this recommendation will help, please do not hesitate to contact me again if you still have problems with native conditions,