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Biomedical subjects

B R Ringeisen

Publications and source records attributed to B R Ringeisen.

7 recordsLinked to original sources
PubMed2005

Printing of protein microarrays via a capillary-free fluid jetting mechanism.

Current proteomics experiments rely upon printing techniques such as ink jet, pin, or quill arrayers that were developed for the creation of cDNA microarrays. These techniques often do not meet the requirements needed for successful spotting of proteins to perform high-throughput, array-based proteomic profiling. Biological laser printing (BioLP) is a spotting technology that does not rely on solid pins, quill pins, or capillary-based fluidics. The non-contact mechanism of BioLP utilizes a focused laser pulse to transfer protein solutions, thereby eliminating the potential for orifice clogging, air bubbles, and unnecessary volume loss potentially encountered in commercially available spotting technologies. The speed and spot-to-spot reproducibility of BioLP is comparable to other techniques, while the minimum spot diameter and volume per printed droplet is significantly less at 30 microm and approximately 500 fL, respectively. The transfer of fluid by BioLP occurs through a fluid jetting mechanism, as observed by high-speed images of the printing process. Arraying a solution of BSA with subsequent immunodetection demonstrates the reproducible spotting of protein in an array format with CVs of <3%. Printing of the enzyme alkaline phosphatase followed by a positive reaction with a colorimetric substrate demonstrates that functional protein can be spotted using this laser-based printer.

Alkaline Phosphatase↗
PubMed2004

Biological laser printing of genetically modified Escherichia coli for biosensor applications.

One of the primary requirements of cell- or tissue-based sensors is the placement of cells and cellular material at or near the sensing elements of the device. The ability to achieve precise, reproducible and rapid placement of cells is the focus of this study. We have developed a technique, biological laser printing or BioLP, which satisfies these requirements and has advantages over current technologies. BioLP is capable of rapidly depositing patterns of active biomolecules and living cells onto a variety of material surfaces. Unlike ink jet or manual spotting techniques, this process delivers small volume (nl to fl) aliquots of biomaterials without the use of an orifice, thus eliminating potential clogging issues and enabling diverse classes of biomaterials to be deposited. This report describes the use of this laser-based printing method to transfer genetically-modified bacteria capable of responding to various chemical stressors onto agar-coated slides and into microtiter plates. The BioLP technology enables smaller spot sizes, increased resolution, and improved reproducibility compared to related technologies.

Biological Assay↗
PubMed2004

Biological laser printing: a novel technique for creating heterogeneous 3-dimensional cell patterns.

We have developed a laser-based printing technique, called biological laser printing (BioLP). BioLP is a non-contact, orifice-free technique that rapidly deposits fL to nL scale volumes of biological material with spatial accuracy better than 5 microm. The printer's orifice-free nature allows for transfer of a wide range of biological material onto a variety of substrates. Control of transfer is performed via a computer-aided design/computer-aided manufacturing (CAD/CAM) system which allows for deposition rates up to 100 pixels of biological material per second using the current laser systems. In this article, we present a description of the apparatus, a model of the transfer process, and a comparison to other biological printing techniques. Further, examples of current system capabilities, such as adjacent deposition of multiple cell types, large-scale cell arrays, and preliminary experiments on creating multi-layer cell constructs are presented. These cell printing experiments not only demonstrate near 100% viability, they also are the first steps toward using BioLP to create heterogeneous 3-dimensional constructs for use in tissue engineering applications.

Animals↗
PubMed2002

Generation of mesoscopic patterns of viable Escherichia coli by ambient laser transfer.

We have generated mesoscopic patterns of viable Escherichia coli on Si(1 1 1), glass, and nutrient agar plates by using a novel laser-based transfer process termed matrix assisted pulsed laser evaporation direct write (MAPLE DW). We observe no alterations to the E. coli induced by the laser-material interaction or the shear forces during the transfer. Transferred E. coli patterns were observed by optical and electron microscopes, and cell viability was shown through green fluorescent protein (GFP) expression and cell culturing experiments. The transfer mechanism for our approach appears remarkably gentle and suggests that active biomaterials such as proteins, DNA and antibodies could be serially deposited adjacent to viable cells. Furthermore, this technique is a direct write technology and therefore does not involve the use of masks, etching, or other lithographic tools.

Escherichia coli↗
PubMedDate not supplied

Picoliter-scale protein microarrays by laser direct write.

We demonstrate the accurate picoliter-scale dispensing of active proteins using a novel laser transfer technique. Droplets of protein solution are dispensed onto functionalized glass slides and into plastic microwells, activating as small as 50-microm diameter areas on these surfaces. Protein microarrays fabricated by laser transfer were assayed using standard fluorescent labeling techniques to demonstrate successful protein and antigen binding. These results indicate that laser transfer does not damage the active site of the dispensed protein and that this technique can be used to successfully fabricate a functioning protein microarray. Also, as a result of the efficient nature of the process, material usage is reduced by two to four orders of magnitude compared to conventional pin dispensing methods for protein spotting.

Equipment Design↗