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Introduction
The original colony-forming assay (CFA) was published in 1966 independently by Bradley and Metcalf in Australia and Pluznik and Sachs in Israel. The assay was performed in agar and detected a population of cells that gave rise to both granulocytes and macrophages. This population, then called CFU-C or Colony-Forming Unit - Culture. This population is now usually called the granulocyte-macrophage colony-forming cell (GM-CFC or CFC-GM). In 1971, Axelrad and his colleagues used a plasma clot culture to detect erythropoietic precursor cells, designated colony-forming units - erythroid (CFU-E). Shortly afterwards, Iscove and his colleagues developed an equivalent assay, but using methylcellulose. The use of methylcellulose as a semi-solid immobilizing medium to grow colonies of primitive lympho-hematopoietic cell populations has now become the norm. In 1982, the assay, which had up to that time been performed as 1ml cultures in 35mm Petri dishes was miniaturized down to 100µl cultures. This miniaturization eventually became the HALO®™ Platform which can be performed in both 96- and 384-well plates. Despite the many drawbacks of the colony-forming assay technique, it is still used by many investigators today.
HemoGenix®® now provides the miniaturized version of the colony-forming cell assay in kit form. It is called CAMEO™-4 and can be used to detect up to 15 different lympho-hematopoietic cell populations from 5 species. The table below compares the normal colony-forming cell assay with CAMEO™-4.
The colony-forming cell assay has been used for numerous applications since the technique was first described. CAMEO™-4 (Colony Assay Miniaturization with Enumeration Output) is the first Colony-Forming Cell Assay to be produced and sold in this format. There are several advantages to using CAMEO™-4 instead of the traditional macro format. These are described below.
Characteristics of the CAMEO™-4 Colony-Forming Cell Assay Platform
The table below shows the differences between the traditional macro colony-forming assay technique and CAMEO™-4.
| | Colony-Forming Cell Assay: (Macro Format) | CAMEO™-4 (Mini Format) |
| Type of Assay: | Differentiation | Differentiation |
| Type of culture: | Methylcellulose | Methylcellulose |
| Cell growth: | Clonal | Clonal |
| Parameter measured: | Cell colonies | Cell colonies |
| Readout: | Manual | Manual |
| Format: | 35 mm Petri dishes | 4-wells in 35 mm Petri dishes |
| Growth surface area: | 8.7 cm2 | 0.97 cm2 |
| No of replicates: | Usually 2-3 x 1ml each | 4 x 100µl each |
| Volume of each assay: | 1 ml | 100 µl |
| Standardization: | Not possible | Possible when performed with HALO® |
Cell Populations Detected using CAMEO™-4
CAMEO™-4 Kits can be obtained to detect each of the following 15 cell populations.
Growth Factor and Cytokine Combinations used to stimulate individual cell populations
* Only included in kits to detect human cell populations
Species-Specific CAMEO™-4 Kits for Cell Populations
Where possible, species-specific growth factors and cytokines are incorporated into the CAMEO™-4 kits.
What's in the CAMEO™-4 Kit Box?
All CAMEO™-4 Kits come with 2 x 15 ml bottles of CAMEO™-4 Master Mix and 50 x 4-well Petri dishes and manual. Please note that no cells or tissues are provided by HemoGenix®.
Requirements for performing CAMEO™-4
Other than the instruments and supplies normally used for tissue culture work there are no special requirements to perform CAMEO™-4. However, the use of syringes and needles to dispense reagents should not be used since they are not accurate and can lead to extremely high coefficients of variation. We strongly recommend the use of repeater pipettes (either manual or electronic) to dispense the methylcellulose-based CAMEO™-4 Master Mix and for plating the reagents.
How to use CAMEO™-4 Colony-Forming Cell Assays
The following protocol shows you how easy it is to use CAMEO™-4 for any cell population from any species.

CAMEO™-96 STD
Coming soon.
References in which the Miniaturization of the Colony-Forming Cell Assay has been used.
Technical Assistance
HemoGenix® is available to answer all questions regarding applications and technical assistance during normal work hours at no charge.