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Christian@mabtech.com last won the day on December 10 2020

Christian@mabtech.com had the most liked content!

About Christian@mabtech.com

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    Mabtech representative

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    Accuratly decribe our official policies and recommendations
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    Stockholm, Sweden

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  1. Hi there! Strong signal in negative wells is a sign of unspecific binding. The blocking may not be complete so that the conjugate binds to the well or there is crossreactivity between the conjugate and some substance in the blocking solution. Which antibodies/system was used?
  2. Hello Kirsten, In all B-cell ELISpots I strongly recommend running total IgG analysis as a positive control. So you have some wells coated with your antigen, and then in others wells were you have coated with anti-IgG. It is good to go down in cell number for the total IgG control since spot numbers will naturally be much higher compared to any antigen wells. If you get spots in total IgG wells you know that the cells are viable and that your ELISpot has worked. If you still then lack spots in you antigen wells it is either due to no antigen specific cells existing or being to
  3. Hello Philip and welcome to the forum! It sounds to me like you are planning on doing a dual ELISpot with the enzymatic approach. We concluded long time ago that it simply does not work. One substrate will generate stronger responses than the other substrate and weak dual positive cells are simply identified as single secreting cells. Furthermore, the readers are rather horrible to use. Mabtech instead invested our time and resources into FluoroSpot. By coupling detection antibodies to fluorophores instead of enzymes correct analysis can be made. Also, with the launch of our o
  4. Hi NN, At Mabtech when we say blank we refer to the the "plate blank" - that is when only substrate and stop solution is added to the wells. This is subtracted by the software before creating the standard curves. We know that not all customers use this kind of blank, but instead chooses to subtract the control with only buffer (incubation buffer or ELISA diluten). Your question, however, concerns whether we recommend subtracting the background values obtained from samples with only medium, e.g. unstimulated control cells. These we do not recommend to subtract, s
  5. Dear Ivana, These batches were sold some time ago before we introduced our ELISA basic formats. Back then the kits were called ELISA development kit and they did not include the A5 reconsititution buffer. However, we kept the product code the same when we moved to ELISA basic. The standard you got in your kit can be reconsituted in pure PBS.
  6. Dear Tetiana, We know from experience that some patient-samples can sometimes generate strange backgrounds in ELISpot that look like the ones seen in your images. One common theme is that the patients analyzed has an ongoing inflammation in their body from a disease state such as cancer, sepsis or autoimmune disease. I have some speculation as to what could be happening: 1. During widespread inflammation cells in the blood become sticky and can form clumps. After Ficoll separation this is often seen when taking out the PBMC band. The inherent stickiness of the cells leads to more deb
  7. Hey there! We unfortunatly do not have antibodies or ELISA kits for detecting Bachem Exenatide. This is not in our R&D pipeline for development. Sorry.
  8. We recommend doing the pre-incubation with at a cell density of 1million PBMC/ml. The vessel can be a 15ml falcon tube but some people prefer the 5ml falcon tubes because the pellet becomes less "concetrated" with a 5ml tube compared to 15ml. The bottom is more cone-shaped with 15ml tubes. It is smart to loosen the top screw abit so that CO2 can get to the cells easily. If the lid is too tight CO2 cannot get in which is bad for the cells.
  9. That is unfortunate. I checked our setting and Guest should be allowed to upload attachments, no restrictions. However, I did my own testing and yes, the upload function dont seem to work when posting as a guest. This worked before with earlier versions of the forum software. I will contact our supplier and ask for an update.
  10. Dear Lucy! This is fantastic news. Easiest to attach things is to put them into a PPT and then upload it.
  11. Hi Joseph, It should in principle be possible to label MT57 with Alexa488 using NHS ester. However, we have not opted for this route in the human IgA sandwhich system used in fluorospot. In our FluoroSpot Flex system for human IgA we use MT57 as the capture antibody and MT20 as the detection antibody conjugated with a 490 Fluorophore. https://www.mabtech.com/products/flex/X-06G-1 Regarding storage in different buffers I do not know. Will check with our production unit next week when we are back from easter holiday. With pretty high likelihood, we will not know if this antibody
  12. Hey Lucy! For unimmuniced mice you absolutly have to activate B-cell in vitro using our stimulation cocktail. Otherwise, there will be pretty much no spots in the ELISpot. Good luck!
  13. Hi again Lucy, Yes, definitly, this could be the reason. Some antibodies simply dont work well in ELISpot. When we develop new antibody systems we can have 8 different pairs that perform well in ELISA. There are differences, but not massive. However, testing the same 8 pairs in ELISpot and only 1or2 works well. ELISpot requires the absolute best antibodies to work well. That is why our portfolio of Mabtech monoclonals tend to be among the best in the market. Buy our kit and repeat!
  14. Hi Lucy, welcome to the forum! No this certainly looks strange. Way too low spot count. Where have you purchased the polyclonal antibodies against mouse IgG1? At only 50K cells/well, our in-house results look like this:
  15. Hey, When you say "blank" wells It still looks to me like these wells contain spots. So all reagents have been added correctly, otherwise there would be zero spots. One feeling I get is that you use tween in your wash buffer? Right or not? Tween is something we do not recommend. It makes reagents penetrate deeper into the PVDF membrane and this is only beneficial if you do NOT etoh activate the membrane. Since you do perform the etoh activation (which is good, sensitivty of the assay increases) tween gives no benefit. However, it can lead to a purple haze in the membrane. Som
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