Fabrication of biological microarrays using microcantilevers (original) (raw)
Related papers
Bio-Microarray Fabrication Techniques—A Review
Critical Reviews in Biotechnology, 2006
Microarrays with biomolecules (e.g., DNA and proteins), cells, and tissues immobilized on solid substrates are important tools for biological research, including genomics, proteomics, and cell analysis. In this paper, the current state of microarray fabrication is reviewed. According to spot formation techniques, methods are categorized as "contact printing" and "non-contact printing." Contact printing is a widely used technology, comprising methods such as contact pin printing and microstamping. These methods have many advantages, including reproducibility of printed spots and facile maintenance, as well as drawbacks, including low-throughput fabrication of arrays. Non-contact printing techniques are newer and more varied, comprising photochemistrybased methods, laser writing, electrospray deposition, and inkjet technologies. These technologies emerged from other applications and have the potential to increase microarray fabrication throughput; however, there are several challenges in applying them to microarray fabrication, including interference from satellite drops and biomolecule denaturization.
Automated and Multiplexed Soft Lithography for the Production of Low-Density DNA Microarrays
Microarrays (Basel, Switzerland), 2016
Microarrays are established research tools for genotyping, expression profiling, or molecular diagnostics in which DNA molecules are precisely addressed to the surface of a solid support. This study assesses the fabrication of low-density oligonucleotide arrays using an automated microcontact printing device, the InnoStamp 40(®). This automate allows a multiplexed deposition of oligoprobes on a functionalized surface by the use of a MacroStamp(TM) bearing 64 individual pillars each mounted with 50 circular micropatterns (spots) of 160 µm diameter at 320 µm pitch. Reliability and reuse of the MacroStamp(TM) were shown to be fast and robust by a simple washing step in 96% ethanol. The low-density microarrays printed on either epoxysilane or dendrimer-functionalized slides (DendriSlides) showed excellent hybridization response with complementary sequences at unusual low probe and target concentrations, since the actual probe density immobilized by this technology was at least 10-fold l...
The Analyst, 2004
For the first time we report on the production of oligonucleotide microarrays using a highly parallel and highly integrated, pressure driven TopSpot nanoliter dispenser. The system enables non-contact printing of different media like oligonucleotides, DNA or protein solutions. We optimized the printing buffer needed for oligonucleotides microarrays production with respect to two major aspects: microfluidical optimum for droplet dispensing and biochemical coupling efficiency on different commercially available microarray slides. Coefficient of variations (CVs) of generated spot diameters were measured to be smaller than 1% within one single dispensing nozzle and smaller than 1.5% within all 24 parallel nozzles of the printhead for all printing buffers used. No carry-over and no cross-talk was found, in extensive experiments with oligonucleotides. Optimized printing buffer compositions and concentrations for oligonucleotide microarrays were found, as well as optimized coupling protocols. Furthermore, buffers and protocols were adapted to a host of different microarray slides used. With this system, prime critical points of microarray production are solved, leading to high quality high throughput microarray fabrication.
Biosensors and Bioelectronics, 2012
We demonstrate a method to create high density protein microarrays with excellent spot uniformity using photolithography and plasma processing on low cost commercially available microscope glass slides. Protein deposition and fluorescence signal evaluation on these substrates are performed by standard arrayers and scanners. To this end, spots of commercial photoresists (AZ5214, SU8 and Ormocomp ® ) were defined through lithography on glass substrates followed by short SF 6 plasma treatment and selective protein adsorption on these spots with respect to glass (spot to background fluorescence signal ratios 30:1 to 40:1) was demonstrated using model protein binding assays. Among the photoresists tested, Ormocomp was selected since it provided the highest protein binding capacity. No ageing of Ormocomp/glass substrates in terms of protein binding capacity was observed for at least two months. Besides to protein microarrays, DNA microarrays were also developed by spotting streptavidin-biotinylated oligonucleotide conjugates corresponding to wild-and mutant-type sequences of four deleterious BRCA1 gene mutations. For all of the examined mutations, higher specific hybridization signals (1.5-4 times) and improved discrimination ratios between wild-and mutant-type sequences as well as higher spot uniformity and repeatability were demonstrated on Ormocomp/glass substrates with intra-and inter-spot CVs of 8.0% and 4.5%, respectively, compared to commercial polystyrene (intra-and inter-spot CVs 36% and 18%) and epoxy-coated glass (intra-and inter-spot CVs 26% and 20%) slides. Thus, the proposed substrates can be readily applied to protein and DNA microarrays fabrication and, moreover, the described method for selective protein adsorption can be advantageously implemented in various analytical microdevices for multi-analyte detection.
Small, 2010
Biomolecules, including protein A, albumin, and immunoglobulin G, are spotted on top of a nanoporous substrate by using a continuous-flow microspotter (CFM) system, which normally produces spots 3 to 4 orders of magnitude more sensitive than conventional biomolecule printing methods. The spots are observed with a fluorescence scanner. By using the CFM to print spots on nanoporous substrates, an additional order of magnitude increase in signal is observed, which leads to high signal-to-background ratios, highly saturated spots, and a measurable signal at printing concentrations as low as 1.6 ng mL À1 . This technique produces highly concentrated biomolecular spots from dilute samples and significantly increases the sensitivity of sensing platforms.
DNA Microarray Technology: Devices, Systems, and Applications
Annual Review of Biomedical Engineering, 2002
▪ In this review, recent advances in DNA microarray technology and their applications are examined. The many varieties of DNA microarray or DNA chip devices and systems are described along with their methods for fabrication and their use. This includes both high-density microarrays for high-throughput screening applications and lower-density microarrays for various diagnostic applications. The methods for microarray fabrication that are reviewed include various inkjet and microjet deposition or spotting technologies and processes, in situ or on-chip photolithographic oligonucleotide synthesis processes, and electronic DNA probe addressing processes. The DNA microarray hybridization applications reviewed include the important areas of gene expression analysis and genotyping for point mutations, single nucleotide polymorphisms (SNPs), and short tandem repeats (STRs). In addition to the many molecular biological and genomic research uses, this review covers applications of microarray...
A Highly Parallel Nanoliter Dispenser for Microarray Fabrication
Biomedical Microdevices, 2000
We report about the correlation between satellite free droplet release and liquid viscosity in a highly parallel, pressure driven nanoliter dispenser. In extensive studies, we found that for liquids of different viscosities the duration of the pressure pulse is the predominant effect compared to pressure amplitude. This result is of essential importance when actuation parameters have to be adopted for different media like oligonucleotide, DNA or protein solutions as it is the case for the non-contact high throughput fabrication of microarrays . Experiments with oligonucleotides as well as with different proteins showed ascertained carry-over and cross-contamination free printing of DNA and protein microarrays. With it a prime critical point of microarray production is solved, leading to high quality whilst high throughput microarray fabrication. For oligonucleotides printing, we found CVs to be better than 1% within one single dispensing channel and 1.5% within all 24 channels of a 24 channel printhead for each used printing buffer. By optimizing the protein printing buffer the CVs for protein printing were reduced to about 1% within all 24 channels. As a serious practical application test oligonucleotides microarrays were produced using our nanoliter dispenser system. With it a full DNA hybridization experiment was performed. Clear positive signals one hand and no signals in the negative controls on the other hand showed that our system is suited for microarray production.
Non-contact protein microarray fabrication using a procedure based on liquid bridge formation
Analytical and Bioanalytical Chemistry, 2009
Contemporary microarrayers of contact or noncontact format used in protein microarray fabrication still suffer from a number of problems, e.g. generation of satellite spots, inhomogeneous spots, misplaced or even absent spots, and sample carryover. In this paper, a new concept of non-contact sample deposition that reduces such problems is introduced. To show the potential and robustness of this pressure-assisted deposition technique, different sample solutions known to cause severe problems or to be even impossible to print with conventional microarrayers were accurately printed. The samples included 200 mg mL-1 human serum albumin, highly concentrated sticky cell adhesion proteins, pure high-salt cell-lysis buffer, pure DMSO, and a suspension of 5-μm polystyrene beads. Additionally, a water-immiscible liquid fluorocarbon, which was shown not to affect the functionality of the capture molecules, was employed as a lid to reduce evaporation during microarray printing. The fluorocarbon liquid lid was shown to circumvent hydrolysis of watersensitive activated surfaces during long-term deposition procedures.