Hydrophobic multi-well patterning
The microarray quality glass substrates are printed with either a 16- or 96- well hydrophobic patterning, and are available with a number of functional coatings, making the both formats suitable for most microarray applications using DNA, proteins, or other bio-molecules as probes. The black patterning material serves several important functions, one of which is to create the individual wells that act as a hydrophobic barrier preventing cross contamination between the arrays. The well pattern also serves as a registration aid for probe deposition, and a reproducible surface for the adhesion of the silicone superstructure. The absence of well rims makes NEXTERION® multi-well substrates compatible with all microplate arrayers and significantly reduces print times compared to substrates that have recessed wells. The patterned glass substrates have a corner indicator to provide an unambiguous orientation mark. Most modern robotic arrayers are equipped to handle the 96-well microplate formats, and many have pre-programmed definitions for both the NEXTERION® MPX-16 slides and NEXTERION® MPX-96 plates, simplifying the set up process for users. Information on compatible arrayers and detailed instructions for printing into the NEXTERION® multi-well formats are available on request.
Avoidance of cross-contamination
Cross contamination is avoided during multiplexed hybridization as a result of the 16- or 96-well hydrophobic patterning, and the use of the optional self-adhesive silicone superstructures.
The figure shows a pictorial representation of subarray wells from NEXTERION® Slide MPX-16 that were first printed with three distinct nucleic acid probes and then hybridized with various combinations of three complementary, fluorescent-labeled targets. No cross contamination was observed.
NEXTERION® multi-well coated substrates allows users to obtain microarray data with exceptionally high reproducibility. This was demonstrated by hybridizing multiple 10 x 10 DNA arrays with fluorescent-labeled cDNA targets using NEXTERION® Slide MPX-16. Correlation coefficients were obtained by comparing the normalized signal intensity from spots in different subarray wells. An average correlation coefficient of 0.96 was obtained after pair wise comparison of all eight-subarray wells.
Virtually identical subarrays in each well of one NEXTERION® Slide MPX-16.
The excellent inter-slide reproducibility offered by NEXTERION® multi-well coated substrates is attributable to the simultaneous analysis of all subarray assays, and to the improved sample mixing during hybridization within the wells of the superstructure. The figure shows the average correlation coefficient (R2) obtained with NEXTERION® Slide MPX-16 (indicated as MPX) and conventional slides (indicated as Non-MPX). Experiments were conducted as described in the previous figure, but now using multiple slides for same day and day-to-day experiments.
Optimal use of limited target material
The NEXTERION® multi-well coated substrates allow lower target solution volumes to be used compared to conventional slides. Identical probe sets in separate subarray wells of NEXTERION® Slide MPX-16 were hybridized with 7.5 pmol of fluorescent-labeled target (house-keeping gene: GAPDH), which was dissolved in different volumes (60, 45, 30 µL) of hybridization solution. The figure demonstrates that a reduction in target volume results in increased target concentration and thus in improved signal intensities. NEXTERION® Slide MPX also offers cost savings by reducing the amount of target material required without any loss of sensitivity (assuming that the target volume and target amount are reduced equally, keeping the concentration consistent).
Download pdf file 'NEXTERION® Multi-well formats'
SCHOTT Technical Glass Solutions GmbH