Modulus Luminometer From Turner BioSystems

The Modulus Luminometer from Turner BioSystems is a multifunctional, single tube instrument designed to give flexibility for measuring fluorescence, luminescence, and absorbance at a very reasonable price. The machine has a small footprint (32.82cm D x 26.52cm W x 21.39cm H) and you will save space in the lab by having one machine replacing three machines. This is a great purchase, especially if you have a limited budget because you get 3 instruments in one. I was able to purchase this through Fisher Scientific with almost every module attachment for under $9K.

Modulus operates as a dedicated fluorometer, dedicated luminometer, or a combination luminometer/fluorometer. There is also an optional Absorbance Module capable of taking absorbance measurements in the visible wavelength spectrum (360-1100 nm). This means that Bradford, BCA, and Lowry Protein Assays can be used with this machine. The machine can also quantify DNA and RNA by fluorescence using the Quant-iT technologies from Invitrogen. Overall, the machine is very sensitive and gives a broad range, over several orders of magnitude, for luminescence and fluorescence.

The machine uses 1.5 ml standard microfuge tubes for luminescence and 10x10 mm cuvettes for fluorescence or absorption. There is also a mini-cell adaptor that will work with fluorescence only and is great for when you have a limited amount of sample or want to save on reagent volumes, such as with the Quant-iT from Invitrogen.

The instructions are very easy to follow for setting up the different applications; the touchscreen is easy to navigate as well. Perhaps the greatest thing about this machine is it comes with a list of protocols available for download from the applications page of Turner’s website. The machine works with Invitrogen’s PicoGreen and Quant-iT technologies for DNA, RNA, and protein. Here is a basic list of the overall different applications that can be used with the right modules attached. You don’t have to buy every module immediately and can buy when there is more room in the budget.
Fluorescence Applications: DNA/RNA quantification, protein quantification, gene expression assays, enzyme assays. Fluorescent dyes that can be used: Ribogreen, NanoOrange, Cy3, Cy5 and many others.
Luminescent Applications: Luciferase assays, ATP assays, and chemiluminescent immunoassays.
Absorbance Applications: Protein quantification and cell turbidity (OD600)

I primarily use the luminometer for luciferase assays using Promega’s Dual Luciferase Kit. I perform my transfections in 24-well plates and perform the assay as outlined by Promega (100 µl lysis and use 20µl of extract + 100 µl reagent and 1-second integration time). Parameters for luminescence can be modified easily and stored under different protocols (up to 18 user defined protocols) I also use the instrument to determine DNA and protein concentrations using protocols directly from Turner’s website. For DNA, I use the Hoecsht Dye 33258 because it is cheaper than the Quant-iT DNA Assay Kit. For protein, I use Pierce’s BCA Kit and follow the protocol as specified on Turner’s website with no modifications. The luminometer can be attached to a PC with EXCEL spreadsheet and the data transferred after each read. If it is not attached to a PC, the machine will display up to 20 different reads but you must write the data down as it cannot be saved. I prefer keeping it attached to a computer and saving files directly on the computer.

The biggest negative that I have about this machine is that it is a single-tube machine as opposed to a 96-well format or 384-well format. But for a smaller lab that is not doing HTS work, the machine works great. Also, the software that comes with the machine to export the data to a spreadsheet (such as EXCEL) is only available for PC and not Macs.

Overall, this is an excellent machine at a very reasonable price that can be used for multiple applications and assays, while at the same time, not taking up a lot of lab space.