Anti-ErbB2 / HER2 Affibody®分子(FITC) (ab31891)

I would suggest choosing an ErbB2 negative cell line as your negative control. From the literature, I would suggest the human
neuroblastoma cell line SH-SY5Y which I believe would be a suitable negative control.

The ab31891 Anti-ErbB2 Affibody® is not an antibody, but an 'Affibody'. The backbone of Affibody® molecules are derived from a 58 amino acid IgG-binding domain of Staphylococcal Protein A. There is further information on 'Affibodies' on the datasheet for this product. An IgG isotype control works only with antibodies and is not applicable for Affibody® Molecules.

Thank you for your inquiry.

I received the following answer from the lab:

"No, the Her2-binder is denoted Z00477, which has similar characteristics, but another sequence than Z00342 (or ZHER2:342, as it also has been called).

See Orlova et al, Cancer Res 2006; 66 4339-48.

Please make the customer aware that ab31891 is a dimer through its peptide backbone (Z-Z-Cys)."

I hope this information is helpful and wish you good luck for your experiments.

Thank you for contacting us.

We do not have a FITC-conjugated control for Affibodies®. One palternative would be to conjugate a similar Affibody® to FITC, such as ab31908, which is directed against TNF alpha. The two Affibodies® are similar in structure (head-to-tail dimers) but the suitablility of using an anti-TNF alpha Affibody® as a negative control depends on knowing your samples do not contain TNF alpha.

The online datasheet for the ab31908 is here:

Click here (or use the following: https://www.abcam.com/TNF-alpha-Affibody-Molecule-ab31908.html).

The datasheet for our FITC conjugation kit is here:

Click here (or use the following: https://www.abcam.com/EasyLink-FITC-Conjugation-Kit-3-x-10g-FITC-ab102885.html).

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

Thank you for taking the time to complete our questionnaire and contact us. I am sorry to hear you have had difficulty obtaining satisfactory results from this antibody.

The details you have kindly provided will enable us to investigate this case for you and this is also helpful in our records for monitoring of quality.

I would like to reassure you that ab31891 is tested and covered by our 6 month guarantee for use inflow cytometryand human samples. In the event that a product is not functioning in the applications cited on the product data sheet, we will be pleased to provide a credit note or free of charge replacement.

Reviewing this case, I would like to offer some suggestions to help optimise the results. I would also appreciate if you can confirm some further details:

1. I can recommend to aliquot and store the antibody at -20oC as soon as possible, as directed on the datasheet. this will ensure the antibody remains stable and that we can continue to provide our guarantee.

2. I would appreciate if it is possible to provide some data, including positive and negative controls.

3. I can suggest a permeabilization step would be required in this caseas ErbB2 is localized in the cytoplasm and nucleus. Try permeabilizing in 0.2% Triton for 10 minutes.

4. I would appreciate if you are able to provide any more details of the sample preparation? 'Squashing' the cells in PBS may damage them so that staining is affected, and the cells may not be fully dissociated to single cell suspension. I can recommend to try dissociating the cells in trypsin. There is further information on sample preparation on the following webpage:
http://www.icms.qmul.ac.uk/flowcytometry/uses/multicolouranalysis/cellpreparation/index.html

To ensure the sample is of good quality, a viability cell count in trypan blue can be tried. We recommend there should be over 95% viable cellsin the sample to ensure the sample is healthy enough to proceed with staining and givegood results.

5. This antibody will also detect ErbB2 in the mouse cells. and the CD326 antibody may detect CD326 in the mouse cells. Certainly for this ErbB2 antibody, it has not yet been tested in mouse, and may be cross reacting. It would be useful to includeahuman only positive control, such as SK-BR3 cells?

It would be beneficial to optimize the procedure on a known positive expressing cell line first.

6. What percentage of human Erb2 positive cells are you expecting in the tissue sample?

I hope this information is helpful, thank you for your cooperation. Should the suggestions not improve the results, please do not hesitate to contact me again with the further requested details including the results of the human positive control..

Thank you for contacting us.



Affibody® Molecules are not antibodies, and they do not have different isotypes.

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