Frequently Asked Questions

FAQ (& Facts about Streptavidin-PolyHRP and related SDT products)

1) What is PolyHRP? Which polymer is used in making enhanced PolyHRP label?
What makes PolyHRP different from competitor’s products?

2) What do 20, 40 and 80 in the names and codes of SA-PolyHRP conjugates stand

3) How many HRP molecules does one SA-PolyHRP conjugate have?

4) How many HRP molecules are in Aminoethyl-PolyHRP40?

5) How do compare detection power of the different SA-PolyHRP conjugates?

6) Which SA-PolyHRP should I take aiming at maximum sensitivity in ELISA?

7) What is the expected sensitivity level with PolyHRP (in double antibody
sandwich for an antigen)?

8) Which ImmunoPlates should I use when developing HS ELISA with PolyHRP

9) Which coating conditions are optimal for PolyHRP detection?

10) What is the best buffer applicable with SA-PolyHRP?

11) Why other blocking buffers and stabilizers are not recommended for working with SA-PolyHRP?

12) What is the optimum dilution of SA-PolyHRP conjugates in ELISA?

13) Is SA-PolyHRP applicable in the assays on a microarray platform?

14) What is the difference between your SA1-HTS, SA1-HTS-E, SA1 and SA3-RHT stabilizers?

15) I obtain with SA-PolyHRP80 higher sensitivity in my ELISA for an antigen
but background also becomes larger. Is there any way to improve
signal-to-noise ratios? What should I do to optimize performance?

16) Despite the higher positive signals with SA-PolyHRP I also see an
increased background in my assay system. I saw no or less background when
I worked with a conventional, non-polymeric SA-HRP conjugate. What is the
reason for emerging background?

17) What is the lot to lot variability of the PolyHRP conjugates?

18) For the SA-POLYHRP40, do you mean it can be treated as a big molecule which consists of one
Streptavidin linked to a polyHRP40(40*5 HRP)? I am wondering what is the ratio of the SA to PolyHRP40? How is this ratio measured?

19) I have a question about the storage of #SP20C/#SP40C/#SP80C. Your CoA recommends
Storage: "-20°C (-15°C/-25°C). Do not store below -25°C!"
What is the implication for this storage requirement? Is product degraded below -20°C/ -25°C?

20) Would you be able to provide the molecular weights for the
Streptavidin-PolyHRP product line?

21) What is the average molecular weight of casein in the UCDB solution?
I experienced steric hinderance of my protein when I used BSA as a blocker so I wonder if casein is smaller than BSA or not.

22) I was hoping to get some information on your AEP40 product. I wondered what is the molecular mass? Or how can I work out the molar ratio of AEP40 to IgG antibody when performing conjugation?
I would typically use a 12x molar ratio of HRP to IgG antibody when carrying out standard conjugation, giving antibodies with ~1.5-3 HRP/molecule of Ab. How would I go about this with AEP40?

23) Are you able to provide the host species (if applicable) of Streptavidin-PolyHRP40?

24) Do you have any data or recommendations using these products for IHC, if using a biotinylated secondary antibody?
Are these products suitable for IHC procedures (if using a biotinylated secondary antibody)?
Are there issues penetrating the cell due to the large size of the compound?
Do you have any data if one would select the smaller poly HRP products over the more active HRP-80?
Are there any cell penetration concerns with the larger version that have been observed?
Could you supply titer/concentration info for these products?
For the Goat anti mouse IgG (H+L) Poly-HRP40 product, is there data on how many HRP molecules are on each antibody and is there reason to believe that this would perform better or worse in an IHC protocol than the products in question above, question 1?
If so do you have a recommendation for a secondary AB?
Are you able to provide the host species (if applicable) of Streptavidin-PolyHRP40?

25) How many streptavidin molecules are present in one Strptavidin Poly HRP 80 and Streptavidin Poly HRP 40?

26) How many biotin binding sites are present in Strptavidin Poly HRP 80?

27) What are the molecular weights of Anti- Human IgG Poly HRP 80 and Anti- Human IgG Poly HRP 40?

28) Do you have binding data for Streptavidin Poly HRP 80 precomplexed with any detector with biotin ( one step) vs sequential binding of detector with biotin and then adding of Streptavidin Poly HRP 80 ( 2 step detection)?