A Plate of Chips
Something New on the Menu for Microarrays
Overview
DNA and protein microarrays printed on glass or membrane-coated microscope slides are widely used in scientific research today. This approach has provided researchers with the opportunity to investigate thousands of gene sequences or proteins in a single experiment. However, there is a growing demand for even higher throughput microarray assays.
Example of array spotted into a microplate well.
Genomic Solutions, the market leader in DNA and protein microarraying, now offers the capability to multiplex array experiments by printing microarrays into the wells of microtiter plate wells. This technology is available on both the MicroGrid II and the OmniGrid Accent microarrayers: the former holds up to 16 target microplates, while the latter is capable of holding up to 6 target microplates. Arrays can be printed into 96- or 384-well plates, and in a circular or square layout, to maximize use of the available area in the wells.
Hardware and software upgrades are available for both instruments, allowing users currently printing on slides to easily convert to plate arraying. In addition, it is very easy to switch between the two applications; a useful feature for core laboratories with multiple customers performing different types of assays.
A typical experiment might involve printing the same set of samples into each well of a microtiter plate and then hybridizing each array with a different test and/or control sample. In this way you can perform 96 different assays at the same time on a single substrate. Since each well can hold over 1000 sample spots, this represents over 1.6 million individual hybridization assays if the Microgrid was used to its full capacity. This obviously represents a significant increase in throughput.
MicroGrid
Since sample stability might be an issue when performing longer print runs, both microarrayers can maintain a cooled environment for the source plates. This is especially important for protein printing, which is rapidly gaining popularity in the research community. Protein samples are often printed onto membrane-coated surfaces, and both of the arrayers mentioned have customizable parameters designed to optimize this process and prevent damage to the often delicate surfaces.
Another advantage of printing into microplates is that there are many instruments readily available to automate processing of these 8 x 12cm substrates. This makes the technology more attractive to high throughput assays -- for example testing a battery of unknown compounds for reactivity against a known library of substrates. We envision that such a multiplexed approach will enable researchers to drive the advancement of microarray production into new application areas such as micro ELISA assays, diagnostic arrays, high throughput protein interaction studies and chemical or other small molecule screening.
OmniGrid Accent
The BioRobotics MicroGrid II has the capacity to hold 16 microplates while the GeneMachines OmniGrid Accent is capable of holding 6 microplates. In both cases this enables a researcher to improve assay production by up to a factor of fifty, compared to current microarray methods.
In the following tutorial, we will list some of the common challenges for plate arraying and protein arraying and our solutions to these challenges.
Click here to read the complete tutorial.