Laser-assisted bioprinting at different wavelengths and pulse durations with a metal dynamic release layer: A parametric study.

For more than a decade, living cells and biomaterials (typically hydrogels) are printed via laser-assisted bioprinting. Often, a thin metal layer is applied as laser-absorbing material called dynamic release layer (DRL). This layer is vaporized by focused laser pulses generating vapor pressure that propels forward a coated biomaterial.

Detailed specificity analysis of antibodies binding to modified histone tails with peptide arrays.

Chromatin structure is greatly influenced by histone tail post-translational modifications (PTM), which also play a central role in epigenetic processes. Antibodies against modified histone tails are central research reagents in chromatin biology and molecular epigenetics. We applied Celluspots peptide arrays for the specificity analysis of 36 commercial antibodies from different suppliers which are directed towards modified histone tails.

Chromatin methylation activity of Dnmt3a and Dnmt3a/3L is guided by interaction of the ADD domain with the histone H3 tail.

Using peptide arrays and binding to native histone proteins, we show that the ADD domain of Dnmt3a specifically interacts with the H3 histone 1-19 tail. Binding is disrupted by di- and trimethylation of K4, phosphorylation of T3, S10 or T11 and acetylation of K4. We did not observe binding to the H4 1-19 tail.

Synthesis of peptide arrays using SPOT-technology and the CelluSpots-method.

Peptide synthesis on cellulose using the SPOT technology follows the standard Fmoc-chemistry and can be performed manually or automated. This method allows the synthesis of low-cost peptide arrays containing around 900 large spots of addressable peptides on a cellulose sheet of 19 cm x 29 cm. These peptides can be cleaved from the cellulose support by ammonia gas and afterward spotted on glass microchips.

Use of complex DNA and antibody microarrays as tools in functional analyses.

While the deciphering of basic sequence information on a genomic scale is yielding complete genomic sequences in ever-shorter intervals, experimental procedures for elucidating the cellular effects and consequences of the DNA-encoded information become critical for further analyses. In recent years, DNA microarray technology has emerged as a prime candidate for the performance of many such functional assays. Technically, array technology has come a long way since its conception some 15 years ago, initially designed as a means for large-scale mapping and sequencing.

Antisense inhibition of RNase P: mechanistic aspects and application to live bacteria.

We explored bacterial RNase P as a drug target using antisense oligomers against the P15 loop region of Escherichia coli RNase P RNA. An RNA 14-mer, or locked nucleic acid (LNA) and peptide nucleic acid (PNA) versions thereof, disrupted local secondary structure in the catalytic core, forming hybrid duplexes over their entire length. Binding of the PNA and LNA 14-mers to RNase P RNA in vitro was essentially irreversible and even resisted denaturing PAGE.

Peptide nucleic acids on microarrays and other biosensors.

The analysis of biomolecules using microarrays and other biosensors has a significant role in molecular biotechnology, and will become even more important in the future as a versatile tool for research and diagnostics. For many applications, the synthetic DNA mimic peptide nucleic acid (PNA) could be advantageous as a probe molecule, owing to its unique physicochemical and biochemical properties. PNA exhibits superior hybridization characteristics and improved chemical and enzymatic stability relative to nucleic acids.

Peptide nucleic acid microarrays.

A fast and economical procedure for the production of peptide nucleic acid (PNA) microarrays is presented. PNA oligomers are synthesized in a fully automatic manner in 96-well plates using standard Fmoc chemistry. Subsequently, the oligomers are released from the support and spotted onto glass or silicone slides, which were activated by succinimidyl ester.

PNA microarrays for hybridisation of unlabelled DNA samples.

Several strategies have been developed for the production of peptide nucleic acid (PNA) microarrays by parallel probe synthesis and selective coupling of full-length molecules. Such microarrays were used for direct detection of the hybridisation of unlabelled DNA by time-of-flight secondary ion mass spectrometry. PNAs were synthesised by an automated process on filter-bottom microtitre plates.

Molecular haplotyping at high throughput.

Reconstruction of haplotypes, or the allelic phase, of single nucleotide polymorphisms (SNPs) is a key component of studies aimed at the identification and dissection of genetic factors involved in complex genetic traits. In humans, this often involves investigation of SNPs in case/control or other cohorts in which the haplotypes can only be partially inferred from genotypes by statistical approaches with resulting loss of power. Moreover, alternative statistical methodologies can lead to different evaluations of the most probable haplotypes present, and different haplotype frequency estimates when data are ambiguous.