Kronos Dio AB 2550

Circadian Rythm Bioluminometer. Real-time reporter assay with 8 dish incubator and multicolor measurement system.

Installation in One Week !!! For Only 33 100 $ 29 000 €

Find Also our

Gentaur Kronos Dio AB 2550 is a luminescence monitoring tool to observe gene expressions with bioluminescent markers under long-term culture. Can be used in studies of internal biological clock, circadian rhythms in organisms, gene silencing, drug stimulation, etc. Kronos Dio is equiped with cell culture system within its housing to provide real-time periodical luminescence measurement with multi-color luciferase assay, enabling users to analyse the effects of complex factors influencing gene expression in the cell or the tissue. Internal temperature control (range: 20 to 45 °C) and carbon dioxide circulation allows for convenient cell culture over a long period of time.

Kronos Dio – Gene expression analysis and bioluminescence

The mutual adjustment of the expression of various genes within a cell a fundamental control process at the work within all living bodies, which is to say that t her e is a gene expr ession network. To analyze this kind of adjustment mechanism, the amount of mRNA, which is a transcript product or the amount of protein, which is a translation product can be masured directly by Kronos Dio. However, the reporter gene assay using luciferin-luciferase reaction is widely used because the expression can be quantitatively monitored more easily and more sensitively.

GFP and firefly luciferase are used as a reporter protein. GFP is fluorescent protein and it is widely used as a reporter of the gene expression. The search results of PubMed in 2005 are shown in the table above. One characteristic point is that in comparing total number of hit, the number of GFP is larger but, luminescent protein is more frequently used for studies related to transcription factors. GFP is an extremely stable protein that absorbs light of 470 to 490 nm and emits green fluorescence. It does not require a luminescent substrate such as luciferase, so it is advantageous in terms of cost, and it is a very convenient reporter when confirming the presence or localization of expression over time with Kronos Dio.

Luciferin shows specific luminescent reactions with luciferase and has few nonspecific reactions, therefore its S/N is satisfactory and it has excellent quantitativeness. It is also considered that cell toxicity from luciferin is small, so that it is possible to monitor fluctuation of transcriptional activity in real-time for extend periods by just resolving luciferin in the medium. However, when measuring fluctuations of expression over time, the fact that GFP is a stable protein becomes a disadvantage and it becomes difficult to monitor subtle difference. (It has become possible to obtain GFP with a shorter life in order to compensate for this disadvantage.) Moreover, for measuring the expression amount of the gene over time, it is necessary to assume that excitation light irradiation may easily damage the cell. Firefly luciferase is a protein with a molecular-size of approx. 62kDa, and it is normally considered as having a shorter half-life of around 3 hours. Luciferase with an even shorter life can also be used. Luciferin, the luminescent substrate is sold as an item enclosed in a kit together with a crystal product, cytolysis agent and reactive reagent, so it is utilized according to different needs.

As mentioned at the beginning, the method of measuring the amount of mRNA is also used normally. When this method is used, a cell needs to be crushed to extract RNA, so when measuring temporal changes, it is necessary to prepare cells of the same quality for the amount equivalent to the number of measurement times. Besides, RNA needs to be extracted within a limited time, so it becomes quite a serious task. It is also known that there is not necessarily a correlation between the amount of RNA and the amount of the translation when comparing the amounts of the two kinds of RNA.

Kronos Dio: Real-time Gene Expression Measurement in Living Cells AB-2550

35mm culture dishes
Luminescence measurement device for real-time reporter assay

AB-2550 Kronos Dio

AB-2550 Kronos Dio is a luminescence measurement device (luminometer) that equips a photomultiplier tube as a detector. This device is suitable to monitor gene expression of culture cells and cultured tissue slice at fixed intervals over a period of several hours to several days using 35mm diameter culture dish as a sample container.
For the long term cultures, it is possible not only to control temperature in the cabinet by the air circulation but also to introduce CO. Additionally, because an optical filter is built in, it is possible to monitor up to three kinds of gene expression using luciferase with different colors of luminescence.

Flow of sample measurement using Kronos Dio

Kronos Dio measures luminescence of the cells in the culture dish.

To measure living cells

In the chamber, the temperature is kept at a constant level and CO2 gas can be introduced. For general cultures of cells, constant temperature conditions of 30 to 40 degrees are essential. AB-2550 Kronos Dio is equipped with a constant temperature device using Peltier device, so it is possible to maintain the temperature in the chamber at a constant level (25 to 45 degrees:room temperature 25 degrees). Moreover, for cells that need to be cultured with CO2 introduced, it is possible to maintain CO2 density at 5% (CO2 sensor and regulator equipped)

Applicable to long term measurements and multicolor luminescence measurement

Kronos Dio can hold up to eight 35 mm diameter culture dishes in the chamber. The turntable has a structure which no stray light can cause interference between each dish. Because dishes can be exchanged easily by opening the door of the chamber, stimulation with drugs can easily be performed. After the door is closed, temperature rises promptly, so a stable culture condition can be obtained. Luminescence is measured for long time at regular intervals. This is applicable to multicolor assay measurement to obtain luminescence of three colors using one substrate because a color separation mechanism is built-in.