Although a mature product category, microplate readers are evolving towards greater functionality, flexibility, and throughput. All top instrument makers are focusing at least some efforts on multiplexing.
“Vendors are introducing evolutionary improvements in performance, reliability, user interface, and support,” says Xavier Amouretti, product manager at BioTek Instruments (Winooski, VT).
Users, according to Mr. Amouretti, expect a short learning curve, user-friendly software, and instrument reliability.
When plate densities were increasing during the last decade in response to very high-throughput studies, it appeared that plate readers would require upgrades as well. Luckily, experiment densities have stabilized, with life science researchers turning to smaller, “smarter” screens. 384-well plates have become standard in industry, while 96 wells is quite common in academic research.
However, the desire to consume less sample and fewer reagents continues. BioTek has developed the Take3 Micro-Volume Plate accessory that works on principles similar to Thermo’s NanoDrop UV/Visible analyzer. After depositing 2 μL samples on the 16- or 48-spot plate, the second optical surface engages, and the plate is read in the standard manner.
Not that ultra-dense plates are completely out. “The emergence of the 3456-well format has created demand for screening an entire compound library on one plate,” says Dr. Michael Fejtl, international sales and marketing specialist at BMG Labtech (Ortenberg, Germany).
One indication of the maturity of the plate reader market is the number of vendors involved, more than 25 in the United States, according to the Lab Manager website. With so many vendors competing for modestly growing research and high-throughput markers, there has been a steady stream of technologic innovation and price reductions.
An example of such innovation is Douglas Scientific’s (Alexandria, MN) ArrayTape. Instead of an injection-molded plastic microtiter plate or microarrays, the product is a continuous polypropylene (or polystyrene, polycarbonate) strip embossed with reaction wells that hold less than 800 nL of test fluid. Wells are arranged in familiar SBS format (96, 384, 1536, etc., wells), but the savings in reagent and solvent are as much as 90 percent compared with standard microwells.
Anita Kant, Ph.D., application scientist at Molecular Devices (Sunnyvale, CA), has compiled a list of things to look for in a microplate reader. These include specific applications, the number of expected users, sensitivity, current vs. future needs, system versatility, and single vs. multimode reading capability.
To these, Dr. Fejtl adds upgradeability and multiplexing. “It should be easy to employ different detection technologies such as absorbance and fluorescence in a single experiment,” he says.
“Single mode is less expensive, but that may not satisfy future needs,” says Dr. Kant. Nevertheless, multimode (and some other) capabilities may be added later on, provided the instrument can handle upgrades.
Users are also big on ease of use, reliability, robustness, validation capabilities, throughput, automation, and service. Ease of use includes the user interface and software; validation capabilities, once solely the domain of environmental, forensics, and pharmaceutical labs, are gaining popularity among non-regulated industries as well. Automation and throughput are significant factors for medium- to high-throughput labs, but not to academic and basic research organizations.
EZ Read 400 Flexi Reader
- Allows selection of up to four filters of any wavelength from 400 nm to 750 nm, in addition to four standard ELISA filters of 405, 450, 492 and 620 nm
- PC-controlled using Biochrom’s easy to use ADAP 2.0 software
- Optional ADAP 2.0 Plus software allows users to quickly and easily design methods for instant data analysis using standard curves or cut-offs
Synergy H1 and Synergy H4 Hybrid Multi-Mode
- Combine two detection technologies in one unit to create true hybrid systems
- Both systems are integrated with flexible monochromator-based fluorescence optics
- The Synergy H4 includes sensitive filter-based optics (option for Synergy H1 systems) for an endless array of current and future assay protocols.
- Atmospheric control unit (ACU) now available for fully regulated independent control of both oxygen (O2) and carbon dioxide (CO2) levels within your multimode microplate reader
- Measures multiple detection modes including Fluorescence Polarization (FP), Fluorescence Intensity, Time-Resolved Fluorescence (TRF), and more
- Extended cell-based experiments can now even be performed without user intervention
BMG Lab Technologies
- Offers luminescence scanning to complement its existing 3D and fast absorbance and fluorescence scanning capabilities
- Allows the emission spectra of stable luminescent signals to be recorded at 1 nm resolution using the instrument’s emission monochromators
- Format flexibility allows Tecan’s NanoQuant Plate™ for very low volume absorbance measurements to be used alongside virtually all 6- to 1,536-well plate formats
- Features double orbital shaking for more efficient reagent mixing, an Opitmal Read (OR) function for reliable cell-based measurements, and precisely controlled pipetting