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Cobalt Colorimetric Assay Kit

Catalog #: K505

Product Details

Cat # +Size K505-100
Size 100 assays
Detection Method Absorbance (475 nm)
Species Reactivity Mammalian
Applications The assay is linear in the range 3 to 50 nmol (0.18-3 µg) Cobalt, with a detection limit of ~ 3 nmol (or ~15 µM, 0.18 µg).
Features & Benefits • Simple procedure; takes only 20 minutes
• Fast and convenient
• The BioVision Cobalt Assay kit takes advantage of the reaction of Co²ᶧ with mercaptoethanol in basic media.
Kit Components • Cobalt Reagent
• Cobalt Chloride Standard (1.0 µmol)
Storage Conditions -20°C
Shipping Conditions Gel Pack
USAGE For Research Use Only! Not For Use in Humans.


Cobalt is a hard, lustrous, grey metal, a chemical element (symbol Co, atomic number 27 and atomic mass 58.9). Cobalt is an essential trace-element for all multicellular organisms as the active center of coenzymes called cobalamins. These include vitamin B-12 which is essential for plants and animals [1]. Cobalt is also an active nutrient for bacteria, algae, and fungi, and may be a necessary nutrient for all life. Cobalt, particularly the Co²ᶧ species, forms complexes with a large number of organic and inorganic molecules with a range of extinction coefficients in the visible range. The BioVision Cobalt Assay kit takes advantage of the reaction of Co²ᶧ with mercaptoethanol in basic media. Under the condition, Cobalt forms a complex with a strong absorbance band at 475 nm. The metal ions Fe²ᶧ, Cu²ᶧ, Ni²ᶧ, Zn²ᶧ, Mn²ᶧ, exhibit less than 10% interference at this wavelength. The kit provides a quick simple accurate method of quantitating Co²ᶧ in a variety of samples.

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Can this kit be used with samples like bacteria, plants, drosophila, yeast etc?
We have optimized the kit with mammalian samples. However, theoretically these kits should work with samples from multiple species/sources. Since the optimal conditions depend on the sample type, the protocol has to be be adapted to fit the samples for efficient results. Please refer to this kit's citations to see what kind of samples have been used with this kit other than mammalian samples.
Can we use frozen samples with this assay?
Fresh samples are always preferred over frozen samples. However, frozen samples can also be used, provided, they were frozen right after isolation, were not freeze thawed multiple time (for which we recommend aliquoting the samples before freezing) and have been frozen for relatively short periods.
Can we use a different wavelength than recommended for the final analysis?
It is always recommended to use the exact recommended wavelength for the most efficient results. However, most plate readers have flexibility in their band width of detection in increments of +/- 10 nm. Depending on this flexibility range, you can deviate from the recommended wavelengths within limits.
What is the exact volume of sample required for this assay?
There is no specific volume we can recommend for the amount any sample to be used since it is completely sample concentration and quality based. You have to do a pilot expt with multiple sample volumes to determine the optimal volume which gives a reading within the linear range of the standard curve. Please refer to the citations for this product to see what other clients have used with similar sample types.
Do you have trial sizes of this kit?
Unfortunately, we do not have trial sizes of this kit available. However, if you are based in the US or Canada, we will give you a 10% off list price introductory discount on its purchase price. If you are based out of this area please contact your regional BioVision distributor.
What is the shelf life of this kit?
This kit is good for 12 months from the date of shipment in the unopened form when stored at the appropriate temperature and appropriate conditions. After opening and reconstitution, some of the components in this kit are good for 2 months at -20°C. Please refer to the datasheet for storage information and shelf life of each of the components.
Why are my standard curve values lower than those shown on the datasheet?
There are multiple factors which influence the signals like the incubation times, room temperature, handling etc. In general, to increase the value of the standards, you can increase the incubation time. As long as the standard curve is linear, it should be fine to use, since all of your samples will also be measured under the same conditions on this curve.
How do I normalize my samples against protein concentration
You can use a protein quantitation assay on the supernatants you get from cell/tissue lysates or with any other liquid sample in the assay buffer.
Can we purchase individual components of this kit?
Yes, you can purchase any of the kit's components without the whole kit. Please refer to the component Cat #s mentioned on the datasheet for ordering.
Can we use an alternate buffer for sample preparation (cell lysis, sample dilutions etc)?
Our assay buffers are optimized for the reactions they are designed for. They not only contain some detergents for efficient lysis of your cells/tissue, but also contain some proprietary components required for the further reactions. Therefore, we highly recommend using the buffers provided in the kit for the best results.
Should I make a standard curve for every expt I do, or is one curve/kit enough?
Yes, I would strongly recommend you to do the standards every time you do the expt. There is always a chance that something was done differently that day and we do not want any conditions to differ between standards and samples.
Does this kit measure free cobalt or bound cobalt?
The kit takes advantage of the reaction of Co2+ with mercaptoethanol in basic media. Under the condition, the free Cobalt forms a complex with a strong absorbance band at 475 nm. The kit measures free cobalt and not bound cobalt.