Biomedical subjects

A Hatch

Publications and source records attributed to A Hatch.

3 recordsLinked to original sources

PubMed2001

A rapid diffusion immunoassay in a T-sensor.

We have developed a rapid diffusion immunoassay that allows measurement of small molecules down to subnanomolar concentrations in <1 min. This competitive assay is based on measuring the distribution of a labeled probe molecule after it diffuses for a short time from one region into another region containing antigen-specific antibodies. The assay was demonstrated in the T-sensor, a simple microfluidic device that places two fluid streams in contact and allows interdiffusion of their components. The model analyte was phenytoin, a typical small drug molecule. Clinically relevant levels were measured in blood diluted from 10- to 400-fold in buffer containing the labeled antigen. Removal of cells from blood samples was not necessary. This assay compared favorably with fluorescence polarization immunoassay (FPIA) measurements. Numerical simulations agree well with experimental results and provide insight for predicting assay performance and limitations. The assay is homogeneous, requires <1 microl of reagents and sample, and is applicable to a wide range of analytes.

Antibody Specificity↗

PubMed1999

Rolling circle amplification of DNA immobilized on solid surfaces and its application to multiplex mutation detection.

A new method of amplifying short DNA molecules immobilized on a solid support has been developed. This method uses a solid-phase rolling circle replication reaction, termed rolling circle amplification (RCA). The probe consists of a single-stranded DNA primer anchored at the 5' terminus to a solid support and a single stranded DNA template hybridized to the immobilized primer. Here, DNA ligase was used to circularize the template, and DNA polymerase I was used to extend the immobilized primer in a rolling circle replication reaction. This method was used to identify a known polymorphism in BRCA1 exon 5. These results demonstrate that RCA offers considerable promise to facilitate effective mutation screening of DNA using a solid-phase format.

DNA↗

PubMed1995

An easy and economical method to prepare cells for cytologic analyses.

A crucial step in any cytology application begins with the placement of cells on slides in a manner that provides good preservation of cell morphology. Commercial cytocentrifuges are the most commonly used devices for this purpose. However, there are instances when these devices are either not available or not applicable. We devised an easy and economical alternative method to prepare cells for cytologic analysis. The device (cytograv) was easily assembled from common laboratory and office supplies, and produced cell preparations of similar quality as those produced with a cytocentrifuge (cytospin-3). Cellular analyses of biological fluids is one of the most common applications for these kinds of devices. The cytograv device was successfully employed in the identification and verification of a PMN isolation procedure from whole blood. The cytograv device was also successfully used to quantitative increases in the number of PMNs in bronchoalveolar lavage fluid recovered from mice treated with increasing doses of paraquat. These two examples illustrate some of the many possible uses of the cytograv device to provide high-quality preparations for cytologic analyses.

Animals↗