
NOTE: The new Biocolor Sircol™ 2.0 Soluble Collagen Assay is now available! This latest addition to the highly cited family of "Sircol" collagen kits combines an
updated 96-well microplate format with an improved dye formulation to significantly enhance collagen sensitivity and specificity. This makes it possible to directly analyze collagen from complex samples such as conditioned media during 2D or 3D cell culture.
We recommend that new customers use our Sircol 2.0 assay kit as it improves sensitivity, specificity, and user-friendliness; however, we will continue to offer the older, "original" kit as well.
Description
The Biocolor Sircol™ Soluble Collagen Assay is a quantitative dye-binding assay for measurement of both acid-soluble and pepsin-soluble collagens.
The assay can assess the rate of newly synthesized collagen. New collagen is produced during periods of rapid growth and development. New collagen is also generated during inflammation, wound healing and tumor development.
The Sircol Assay can monitor collagen produced in situ, or during in-vitro cell culture. It can also measure in-vitro extracellular matrix formation.
This assay is not suitable for covalent cross-linked collagen. However, the Sircol Insoluble Collagen Assay (S2000) replaces hydroxyproline analysis. This allows the customer to measure insoluble collagen within one working day.
Principle of Method
Sircol™ Dye Reagent contains Sirius Red - a linear anionic dye with sulphonic acid side chain groups. Under assay conditions the Sircol dye binds the basic groups of soluble collagen molecules. Maximal binding occurs in collagens possessing intact triple helix organization as the highly ordered Gly-X-Yn helical structure of tropocollagen further contributes to dye binding. This results in a high degree of dye-collagen specificity. Affinity is progressively reduced during heat denaturation 4ºC due to the unwinding of the triple helix and formation of random chains.
Step 1. Addition of Sircol Dye Reagent to samples containing soluble collagen results in the formation of a collagen-dye complex. This complex then precipitates during the dye incubation period and is subsequently isolated by centrifugation, followed by washing to remove unbound dye.
Step 2. Collagen-bound dye is then eluted and measured spectrophotometrically.
Step 3. The collagen content of unknown samples is quantified by comparison against a calibration curve prepared using a collagen standard supplied with the kit.
Specifications
Product Category: | Extracellular Matrix Assays |
Detection Method: | Colorimetric Detection (556 nm) |
Assay Range: | 0 - 150 µg/ml or 0 - 500 µg/ml (depending on setup) |
Limit of Detection: | 10 µg/ml |
Assay Run-Time: | 1.5 hours |
Sensitivity: | The sensitivity of the Sircol Soluble Collagen Assay is 1.0 µg collagen. Quantities as low as 1.0 µg of collagen can be recovered from a 1 ml volume if the Collagen Isolation & Concentration protocol is used (See Sircol assay manual for more detail). |
Type of Collagen Measured: |
|
Measurements Per Kit: | 110 in total (allows a maximum of 48 samples to be run in duplicate alongside a standard curve). |
Storage (unopened kit): | Room Temperature (RT) |
Manufacturer: | Biocolor Ltd. |
Country of Origin: | United Kingdom |
Suitable Samples
Soluble* collagens from mammalian sources**:
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In-vivo: tissues, cartilages, fluids.
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In-vitro: 2D/3D culture extracellular matrices. Customers wishing to analyze conditioned media should first consider the new Sircol 2.0 assay kit.
* Collagens must be in soluble form, depending on sample this will require prior salt/acid/acid-pepsin extraction.
** Non-mammalian collagens may result in a reduced limit of detection. We recommend use of a collagen standard matched to the non-mammalian species under assay.
Many customers have found that the straightforward sample processing and analysis of Sircol make it a good alternative to conventional hydroxyproline analysis.
Kit Contents
The standard size Sircol™ Soluble Collagen Assay kit (cat. no. S1000) contains:
- Sircol Dye Reagent (1x 110 ml)
- Collagen Reference Standard (1x 5 ml, 0.5 mg/ml soluble Bovine collagen)
- Acid-Salt Wash Reagent (1x 20 ml)
- Collagen Isolation and concentration Reagent (1x 20 ml)
- Alkali Reagent (1x 110 ml)
- Acid-Neutralising Reagent (1x 20 ml)
- 1.5 ml micro-centrifuge tubes for dye-labelling reaction.
- Assay kit manual
Which Sircol Collagen Assay should I use for my application?

Resources
2025 Product References
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Usage
This product is intended for laboratory research use only and is not for use in diagnostic procedures.
Related Products
- NEW: Biocolor Sircol™ 2.0 Soluble Collagen Assay
- Sircol 2.0™ uses an updated 96-well microplate format with an improved dye formulation to significantly enhance collagen sensitivity and specificity.
- Biocolor Sircol™ Insoluble Collagen Assay
- Collagen and Hydroxyproline Assays
- Extracellular Matrix Assays
- Extracellular Matrix Molecules
- Promed Bioscience high-purity collagen biomaterials
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