• Product name
    WST-1 Assay Kit (Cell Proliferation)
    See all Cell viability/proliferation kits
  • Detection method
  • Sample type
    Adherent cells, Suspension cells
  • Assay type
  • Assay time
    4h 00m
  • Product overview

    WST-1 Assay Kit ab65475 is an alternative version of ab65473, our most popular WST-1 Assay Kit (which is also supplied as a ready-to-use reagent ab155902). This kit uses a different WST-1 analog, and also contains a stop solution.

    The WST-1 assay provides by far the easiest and most sensitive means for performing a quantitative cell proliferation assay, cell viability assay, or cytotoxicity assay in mammalian cells.

    The WST-1 assay protocol is based on the cleavage of the tetrazolium salt to formazan by cellular mitochondrial dehydrogenase. The amount of the dye generated by activity of dehydrogenase is directly proportional to the number of living cells. The formazan dye produced by viable cells can be quantified by microplate reader by measuring the absorbance of the dye solution at 440 nm.

    The WST-1 assay protocol is very simple:
    - add the WST-1 assay reagent to the cell culture media and incubate for between 0.5 and 4 hrs
    - shake the plate to mix the contents
    - analyze the amount of formazan dye produced by measuring the absorbance at 440 nm
    This kit contains an optional stop solution to stop the production of formazan dye.

  • Notes

    This kit was previously called Quick Cell Proliferation Assay Kit II, and WST-1 Cell Proliferation Assay Kit.

    The WST-1 assay is add-and-read, and requires no washing, harvesting, or solubilization steps. It is faster, stable, and more sensitive than MTT, XTT, MTS based assays. The assay correlates well with the [3H]-thymidine incorporation assay.

    Review our cell health assays guide to learn more about our other cell viability, cytotoxicity and cell proliferation assay kits.


  • Platform
    Microplate reader



  • Mitochondrial dehydrogenases checked in various cell concentrations at different incubation times (2h WST for each condition)

  • HL60 cell proliferation measured after 24h incubation (37°C/5%CO2) and 2h WST at various camptothecin concentrations

  • HL60 cell proliferation measured after 48h incubation (37°C/5%CO2) and 2h WST at various camptothecin concentrations

  • HL60 cell proliferation measured after 72h incubation (37°C/5%CO2) and 2h WST at various camptothecin concentrations



This product has been referenced in:
  • Hyndman KA  et al. Dynamic changes in histone deacetylases following kidney ischemia-reperfusion injury are critical for promoting proximal tubule proliferation. Am J Physiol Renal Physiol 316:F875-F888 (2019). Read more (PubMed: 30810062) »
  • Tan D  et al. Inhibition of RhoA-Subfamily GTPases Suppresses Schwann Cell Proliferation Through Regulating AKT Pathway Rather Than ROCK Pathway. Front Cell Neurosci 12:437 (2018). Read more (PubMed: 30515082) »
See all 4 Publications for this product

Customer reviews and Q&As

1-6 of 6 Abreviews or Q&A


The primary difference between the quick cell proliferiation assay (ab65473) and quick cell plus proliferation assay (ab65475) is that the ab65475 is more sensitive and more stable.

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Thank you for contacting us and your interest in our products.

The Quick Cell Proliferation Assay Kit (ab65473) and Quick Cell Proliferation Assay Kit II (ab65475) should not be affected by serum in your culture medium. Any differences from the different media which may be used will be accounted for by the control of the same sample and subtracting the readings of such controls from the sample readings. This procedure for this is described in the protocol of both the kits.

Hope this information has been useful for you. Please let me know if you have any other questions.

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Thank you for your enquiry and your interest in our products.

As I understand you are looking for an absolute cut-off value for the OD. This is a comparative assay in which you can let the colour develop for an extended period of time to look at minor differences between various samples.

I would advise to perform the statistical significance analysis on the differences you get form the use of this kit. You need to deem the control sample’s OD at 100% cellular proliferation or 0% cell toxicity and go from there in their comparative analysis.

I hope this information will be useful for you.

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Thank you for contacting us.
I have now received an answer from lab. They say the colour might develop with longer incubation of the samples. However, the machine can detect the absorbance only within a certain limit. Keeping that in mind, we recommend repeated reads and termination of the reaction by adding the stop buffer whenever the desired reading is achieved. The 0.5-4 hrs is just the expected time range within which this is expected to happen.
I hope this information is helpful to you. Please do not hesitate to contact us if you need any more advice or information.
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The phenol red from the sample will be diluted in the reaction buffer to a degree that it will not interfere with the assay.

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Thank you for your enquiry. Currently our new lab promotion allows 20% off ALL orders plus FREE shipping on all orders for 3 months. The requirements to be considered a “New Lab” are the following: The lab is created by a scientist starting a completely new lab. Scientist moving existing lab to a new location. Scientist is a first time grant recipient. If one of these describes you currently, please email newlabdiscount@abcam.com

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