Biography  

Dr. Landers received his Bachelor of Science degree in Biochemistry with a minor in Biomedicine at the University of Guelph (Ontario, Canada) in 1983. He received his doctorate in Biochemistry (with distinction) in 1988 from the Department of Chemistry and Biochemistry at the same University. After a post-doctoral fellowship at the Banting Institute in the School of Medicine at the University of Toronto in 1989, he received a Medical Research Council Fellowship to study with Dr. Thomas Spelsberg at the Mayo Clinic. In Spelsberg's laboratory, he explored new state-of-the-art bioanalytical technologies for developing rapid, sensitive assays for disease diagnosis. At the end of the post-doctoral fellowship (1993), he remained at the Mayo Clinic as the Director of Clinical Capillary Electrophoresis Facility which was established in the Department of Laboratory Medicine and Pathology. His group was involved in the exploration, development and implementation of a number of routine and esoteric CE-based assays for diagnosis of disease. These included separation-based assays for multiple myeloma, amyloidosis, multiple sclerosis, hypoglycemic drug abuse, kidney function, and alcoholism, to name a few. He moved his program to the University of Pittsburgh in 1997, where he filled the position of an Assistant Professor in the Analytical Division of the Department of Chemistry and adjunct member of the University of Pittsburgh Cancer Center. In 1999, he accepted a position at the University of Virginia and currently serves as a Professor in the Department of Chemistry and as a Professor of Pathology in the University of Virginia Health Sciences Center.

[Click here for Dr. Landers's Dept. of Chemistry Biography]

Recent Research  

Current research efforts are focused on the development of microfluidic devices and instrumentation for detection and analysis of biomarkers specific for the diagnosis, prognosis and therapeutic monitoring of cancer from fine needle biopsies.  This development involves the design and fabrication of new chromatographic media for implementation in microfluidic devices used for immobilization of proteins for affinity chromatographic capture of biomarkers.  The new media allows for direct on-column detection of the captured proteins using sandwich type assays as well as interrogation to determine the extents of post-translational modifications.

A second part of this project involves the design and construction of bench top laser induced fluorescence detection systems for use with the microfluidic devices.  This project uses low cost diode lasers excitation, coupled to photodiode based detection, employing optical technology for decreasing the background to promote the sensitivity of the detection.

[Click here for more information about Dr. Ferrance]

A  Fully Integrated Microfluidic Genetic Analysis Device for the Detection of Blood Cancers

We are developing a fully-integrated microdevice capable of DNA extraction, PCR amplifciation and the subsequent electrophoretic separation specifically for the detection of T-cell lymphoma (TCL).  While we have recently reported a fully-integrated device for the detection of bacteria [1], the interrogation of human genomic DNA from whole blood provides new challenges, especially when detecting gene rearrangements correlative with cancer.  Detection of TCL involves the PCR amplification of select sequences in the T-cell gene that are likely to have undergone gene rearrangment.  These PCR fragments represent a polyclonal cell population in normal individuals and a monoclonal cell population in patients with lymphoma in a way that can be discriminated by electrophoretic separation.  In clinical labs, the PCR that follows DNA extraction requires ~3 hours followed by a 40 min capillary electrophoresis separation under single-stranded conditions and utilizing 4-color detection.  While integration of procressing steps is a large advantage over traditional methods, the reduction in the times associated with these lengthy processes is also an important benefit.

[1] Easley, C.J., Karlinsey, J.M., Bienvenue, J.M., Legendre, L.A., Roper, M.G., Feldman, S.H., Hughes, M.A., Merkel, T.J., Ferrance, J.P., Landers, J.P.  Proc. Natl. Acad. Sci. USA, 2006, 109(51), 19272-19277.

DNA Extraction and PCR Amplification Performed in a Single Microfluidic Chamber

Integrated microdevices provide the opportunity to encompass multiple analytical steps on a single device, with the possibility of automating the entire sample analysis process. Current work being developed involves a glass microdevice that has been designed to perform solid phase extraction (SPE) of DNA and IR-PCR (infrared-mediated) amplification in a novel format - with both processes in the same chamber.  This provided an inherent advantage over any microchip-based DNA extract described previously, [1] in that all of the sample DNA is used for nanoliter amplification, improving detection limits by 1-2 orders of magnitude.  A novel solid phase, chitosan-coated magnetic beads, has been developed that has high DNA recoveries (72% ± 6%) using a pH-induced DNA release technique, [2] while eliminating the use of high salt solutions and organics (both potent PCR inhitbitors).  A simple external magnet is used to control the location of the beads in the chamber, removing the need for etching structures (such as weirs or pillars) into the cahnnels, increasing the simplicity of the device design and fabrication.  While previous SPE phases have been composed of materials incompatible with PCR [1] (due to high protein adsorption) the chitosan coating does not affect the efficiency of PCR, allowing the beads to remain in the very same chamber used for PCR.

[1] Legendre, L.A., Bienvenue, J.M., Roper, M.R., Ferrance, J.P., Landers, J.P. Analytical Chemistry, 2006, 78, 1444.

[2] Cao, W., Easley, C.J., Ferrance, J.P., Landers, J.P. Analytical Chemistry, 2006, 78, 7222-7228.

In 2008, Lindsay will begin the Postdoctoral Training Program in Clinical Chemistry and Laboratory Medicine at the Department of Pathology at the University of Virginia.

Recent Research

New Monolith Stationary  Phase for Microfluidic DNA Purification

Microfluidic-based Nucleic Acid Purification in a Two-stage, Dual-phase Microchip

Recent Research

Microwave Polymerase Chain Reaction (PCR)

Spaceflight Therapeutic Drug Monitoring

Micellar Electrokinetic Chromtography (MEKC)

Cell Sorting for Forensic and Genetic Analysis  

Differential extraction (DE) is a well-established technique for the recovery and separation of biological materials from cotton swab samples taken from sexual assault victims.  However, this procedure is time consuming, and has contributed to a backlog of forensic casework samples involving biological evidence. In addition, DE is often ineffective for samples containing sperm cells as a minor component in the presence of excess epithelial cells, resulting in mixed STR profiles that are often difficult to interpret. My research focuses on the improvement of conventional DE methods to increase the purity of the male fraction and enhance the overall speed of analysis.  In addition, my work involves integration of cell sorting with downstream analytical processes in an effort to develop a fully-integrated microdevice capable of genetic DNA analysis.

Elastomer-based Chemo-Mechanical Sensor

This is a collaborative project with Dr. Matt Begley's lab (http://people.virginia.edu/~mrb3h/) in the Civil Engineering Dept. of UVa. Elastomer-based freestanding structure was theoretically demonstrated to be highly sensitive compared to conventional Si-based freestanding structures. The main idea is to develop chemically-selective surfaces on ultra-compliant polymeric microstructures: selective adsorption of molecules leads to mechanical deformation or ¡°buckling¡± that can be used to indicate the presence of pollutants, pathogens, cancer markers, etc.

We have microfabricated freestanding cantilevers, and membranes, and macro scaled elastomer strips to prove the concept of the elastomer-based chemo-mechanical sensing. Protein-substrate interaction (e.g. Avidin-Biotin), DNA-salt interaction have been applied on the freestanding structures. The biological and physical effects of protein and DNA behaviors on surface as well as the surface mechanics can be elucidated besides the sensing application. Various surface functionalization techniques are being explored.

Electric-Field Flow Fractionation for DNA Concentration

In many separation scenarios, a simple preconcentration step between purification steps is highly desired. For example, the elution step on a microchip solid phase extraction column dilutes the DNA and raises the threshold for downstream amplifications. To solve this problem, we are developing electric field-flow based glass/PDMS microdevices to recover concentrated DNA samples from upstream extraction/purification steps.

Recent Research

Passive Valving in Micodevices

Nucleic Acid Purification  

My current research focus involves RNA extraction on a microdevice as a purification step for mRNA profiling for genetic analysis and clinical diagnosis.  A silica-based method has been developed for RNA purification, and has demonstrated effective extraction of RNA from biological samples such as semen and semen stains.  Alternatives to silica-based phases are being explored for their potential for both RNA and DNA purification. DNA extraction from biological sources is another area of focus in my research, using silica-based methods as well as  SPE methods using a charge switch technology developed in our lab, which avoids the use of PCR inhibitors. This new SPE matrix is based on the pH-dependent charge of chitosan, allowing for the capture and release of DNA using buffers that differ in pH.  Work with these and other phases encompasses my research toward the development of a system for total nucleic acid purification from biological samples.

Recent Research

Large Volume Reduction Solid Phase Extraction (vrSPE)

Plastic Solid Phase Extraction (SPE) Microdevices

Recent Research

Protein Separation