Tecans monochromator innovations for microplate readingTecans Quad4 Monochromators Stray light reduction improves sensitivity
Tecans Quad4 Monochromators Stray light reduction improves sensitivity
Tecan DetectionTecan has a solid reputation in producing innovative and high quality automated liquid handling workstations and detection instruments such as microplate readers, microarray related products and washers. Tecan has more than two decades experience in the design, development and production of microplate readers, won several innovation prices and is ISO 9001 and ISO 13485 certified.
Tecan has developed, produced and sold more than 20,000microplate readers globally to academic centers, governmentalinstitutions, universities, the life science, biotech andpharmaceutical industries and the Companys OEM partners. The robustness and longevity of older generation instruments
including the Sunrise absorbance reader, the Ultra, the GENios Pro and the Safire2 is such that many have been, and still are, in daily use in biopharmaceutical screening and research facilities around the world.
The Company has introduced a broad range of technologyinnovations such as fluorescence lifetime detection andQuad4 Monochromators. For Tecan Austria, a very important focus has been the development of the Infinite series of multimode microplate readers and, in particular, monochromator-based multimode microplate readers. These innovations have helped shape the life sciences industry, and will continue to do so.
Monochromator Technologies and products
What is a monochromator?
A monochromator is an optical instrument consisting of anentrance slit, a dispersive element and an exit slit. The dispersiveelement diffracts the light into its optical spectrum, and projects it onto the exit slit.
Rotating the dispersive element moves the spectrum acrossthe exit slit to select the desired wavelength. In principle, thedispersive element could be realized by using glass or silica prisms,however, Tecans monochromators are designed with state of theart concave holographic gratings for highest efficiency.
What is the advantage of a double monochromator?
A single monochromator achieves a stray light suppression of approximately 103. If a monochromator is set for light with awavelength of 500 nm and the detector detects a signal of 10,000counts, light with wavelengths other than 500 nm may create asignal of up to 10 counts. For fluorescence applications, stray lightsuppression of single monochromators might be compromising,as the fluorescent light to be detected is usually much weakerthan 1/1000 of the excitation light.
To achieve a higher level of blocking, Tecan has connected twomonochromators in series. Therefore, the exit slit of the firstmonochromator simultaneously acts as the entrance slit of thesecond monochromator. Size and placement of the slits in thelight path determine the effective wavelength resolution. Bycombining two monochromators, the stray light suppressionreaches a factor of 106.
A stream of innovation for your success
The picture above shows the history of Tecans monochromator-basedmultimode microplate readers. The development of Tecans first Quad4Monochromators-based multimode reader the Safire* startedin 1999, and the Infinite M200 PRO and Infinite M1000 PRO are Tecanscurrent monochromator-based products.
*The Safire has now been phased out.
Infinite M200 PRO
NEW Infinite M1000 PRO
The Quad4 Monochromators technologymakes use of double monochromators forboth excitation and emission. The picturesoutline the double monochromatorsystem architecture on the excitation (left)and the emission sides (right). A sphericalmirror maps the light onto the entry slit,and the grating causes diffraction of thelight into its optical spectrum. Rotation ofthe grating determines which color willpass through the exit slit, which issimultaneously the entry slit for thesecond monochromator. The light is thenfurther diffracted by the second grating.
What is the difference between additive and subtractive monochromators?
In an additive monochromator design, combining two monochromators also doubles the dispersion of the system. For a given slit width, only half of the bandwidth and half of the energy is able to pass through the system. To increase monochromator efficiency, Tecans current monochromators use a special folding of the optical axis to achieve a subtractive monochromator design, causing dispersion of the first monochromator to be canceled out by the second monochromator. A subtractive monochromator design behaves similarly to tunable filters, achieving very good stray light suppression, without the transmission loss of additive monochromators.
Tecans Quad4 Monochromators technology
Tecan started development of its first monochromator-basedmultimode microplate reader in 1999, resulting in the launchof the Safire microplate reader. This was Tecans firstmonochromator-based multimode microplate reader tofeature the Quad4 Monochromators design.This concept places two monochromators (spectral gratings)in series on the excitation as well as on the emission side.
Tecans premium Quad4Monochromators technology
Tecan has further optimized its subtractive Quad4 Monochromatorstechnology to provide more light to the sample and the detector.Premium Quad4 Monochromators feature an improved spectralblocking and stray light reduction down to 2x10-7. Used in theInfinite M1000, this is combined with a flash lamp providing 2xmore optical power, and a switchable flash frequency (patent US 7,088,054) function to optimize TR-FRET based measurements.
In addition to Quad4 Monochromators technology, there is anenormous amount of experience and know-how which flows into thedesign integration and fine-tuning of Tecans monochromator-basedmultimode microplate readers. Tecan uses the subtractiveQuad4 Monochromator principle in both its Infinite M200 PRO andInfinite M1000 PRO multimode readers, providing monochromator-based instruments to suit a variety of market segments.
Tecans Quad4 Monochromatorsmultimode microplate reader chronology
Tecan has over a decade of experience in development ofmonochromator-based microplate readers and related innovations.
Tecan started the development of its first Quad4 Monochromator-based multimode microplate reader in 1999. The Safire multimodereader was launched in 2001, offering absorbance scans,fluorescence excitation scans (emission fixed, excitation range),fluorescence emission scans (excitation fixed, emission range),3D scans (excitation and emission range), wavelength selection in1nm steps, z-focus, optional barcode reading, 1536-well reading and adiode array detector option for high speed absorbance scanning. TheSafire was Tecans first multimode microplate reader with an additiveQuad4 Monochromators design, and featured four adjustable slitssettings (2.5, 5.0, 7.5, 12.0 nm) for fluorescence-based measurements.Adjustable bandwidth settings optimize the performance of theinstrument for resolution and sensitivity by controlling the amount of light in fluorescence mode.
The Quad4 Monochromators technology provides a number ofessential benefits by combining flexibility with sensitivity throughoptimized stray light reduction. The monochromator-based Infinitemicroplate readers do not require any absorbance or fluorescencefilters, offering freedom of wavelength selection, convenience andproviding a cost-effective solution when a broad variety offrequently changing applications are covered. True wavelength flexibility Using Quad4 Monochromators enables good performance
over the whole wavelength spectrum.
Improved sensitivity Stray light and the resulting background noise are the
most critical factors affecting sensitivity. Tecans Quad4 Monochromators effectively reduces stray light down to 10-6.
More accurate readings Using Quad4 Monochromators gives a true spectral scan,
by eliminating the use of cut-off filters.
Extremely fast scan times Using Tecans configuration of Quad4 Monochromators
increases the speed of fluorescence scans compared with microplate readers combining two monochromators with cut-off filters.
With the Safire2 instrument, Tecan introduced the subtractive Quad4 Monochromators technology. The Safire2 offered the option of multichannel absorbance and luminescence reading, as well as fluorescence polarization and an integrated stacker. The number of adjustable bandwidth settings was also extended, to 16 slit options on each the excitation and emission side, providing an enormous range of potential wavelength/bandwidth settings for assay development. Tecan also developed the patented stepless adjustable bandwidth setting (patent US 7,123,398).
With the Infinite M1000, Tecan launched the premium Quad4 Mononchromators, which features a subtractive monochromator design, an integrated solution to provide more light to the sample and detector and improved stray light reduction down to 2x 10-7.
The Infinite M200 offered affordable access to subtractive Quad4 Monochromators technology. The Infinite M200 was relaunched in 2009, with enhanced monochromator performance (accuracy) for DNA quantitation (260/280 nm) and absorbance scanning. The Infinite M200 was also compatible with the recently launched NanoQuant Plate, which allows DNA quantitation in low sample volumes down to 2 l.