POCDx Events Calendar

Kevin Ness, Director of Research and Development
Quantalife, Inc.

Motivated by the principle that nearly all assays are improved with a purified and concentrated sample, I will discuss previous efforts to construct an automated, general sample preparation platform to handle a wide range of ‘complex’ starting samples. The objective is to replace the slow, burdensome, manual techniques currently used in labs and clinics today with rapid, high throughput, lab-on-a-chip technologies. The strategy for sample preparation is to develop a minimum number of plug-and-play modular devices which can be reconfigured in assay-dependent serial layouts. This approach enables the use of general tools to uniquely prepare samples for the maximum number of assays/platforms. Each of the selected sample preparation technologies individually meets a set of design requirements critical to the delivery of a robust and reconfigurable capability: 1) easily integrated into a modular device with minimal fluidic interconnects, 2) ability to handle various sample solution properties (pH, ionic strength, viscosity) and analyte/biological diversity, 3) reagentless or requiring only simple and stable buffers, 4) nearly lossless with low-surface area or force fields which drive the analyte of interest away from the wall, and 5) high-throughput with the ability to handle a large range of volumes.

Based on these requirements, we are developing a suite of devices which use affinity capture, acoustic focusing, dielectrophoresis (DEP), cross-flow electrophoresis, and equilibrium gradient focusing techniques to create “virtual filters” for specific types or sizes of biological particles. Acoustic and dielectrophoretic forces scale with particle volume and therefore act primarily on large particles such as debris (food, pollen, etc.), cells, and bacteria. Equilibrium gradient focusing techniques are utilized to concentrate and fractionate species based on their size/charge and are ideal for capturing nucleic acid. Electrophoresis generally transports all types of biological particles and provides an excellent technique for concentrating samples. I will discuss both single-field and multiple-field configurations to handle a diverse range of starting ‘complex’ clinical and environmental samples.

The model system for device development is the purification and concentration of viruses from clinical nasopharyngeal swabs and nasal washes. At each “virtual filter” stage, sub-populations of analytes (e.g. cells, bacteria, DNA/RNA, viruses) are binned and available for further processing or off-chip analysis. The seminar describes work primarily completed while at Stanford University and Lawrence Livermore National Laboratory.

Amy Herr, Assistant Professor
University of California, Berkeley

The ability to detect disease using molecular biomarkers could greatly reduce the toll that ailments such as heart disease and cancer exact on society. While conventional bench-top proteomic tools are central to current disease biomarker discovery, clinical settings would benefit tremendously from next-generation disease diagnostics having sufficient assay speed and sensitivity to rapidly measure low-abundance biomarkers in small volumes of biological fluids. We have designed and developed biomarker validation and diagnostic microsystems which exhibit compelling sensitivity and specificity – as needed for successful translation of new techniques to the clinic and point-of-care. This talk will address the important advances in surmounting assay performance limitations critical to both protein biomarker validation and subsequent development of clinical diagnostics.

Tanner Nevill, PhD
Fluxion Biosciences

Except for maybe the first billboard displaying ‘Advertise Here’, great ideas don’t sell themselves. You may be convinced that the technology you’re developing is going to change the world, but to be successful you need to convince others as well. I’m going to share my experiences with starting a company, entering business plan competitions and presenting to VCs. Hopefully my past successes and failures (mostly the latter) will be of help to those interested in starting a company out of the lab. This will be an informal discussion, so bring questions.

Bill McNamara, PJM Ventures

Venture capital grows increasingly scarce given the current state of the economy. This is especially true for technologies aimed at the developing world; entrepreneurs might want to solve global problems, but investors need a sizable return on investment. The entrepreneur increases the odds of funding by performing due diligence that speaks to the goals of the investor. I will discuss my experiences with technology transfer and provide some insight into the unique challenges faced by researchers seeking to commercialize technologies for resource-poor markets.

Rick Henrikson, Luke Lee Lab, Bioengineering

I recently had the opportunity to attend the Bioengineering Applications to Address Global Health Conference at Duke University. The conference had a very large focus on point of care diagnostic technologies and barriers to their implementation. I will deliver a brief review of the key points from this conference relevant to point of care diagnostics. I will discuss some recurring themes and emerging initiatives, as well as several interesting technology presentations.

Amador Goodridge, School of Public Health

The interaction between tuberculosis (TB) and the human immunodeficiency virus (HIV) infection poses difficult challenges for the treatment of TB. The diagnosis of TB and the drug susceptibility of the infecting M. tuberculosis could take weeks; and the clinician will not know if the treated individual is on appropriate set of drugs until it is too late. Therefore, the early diagnosis and detection of a successful therapeutic response in infected individuals is urgently needed. This project examines the changes in antibody response to M. tuberculosis lipids between TB patients as a biomarker for monitoring the treatment response.

Danica Helb, Eva Harris Lab, School of Public Health

Each year, approximately 2 million people die from Mycobacterium tuberculosis infections. Current methods to detect and distinguish pulmonary M. tuberculosis and multi-drug resistance (MDR) are inadequate. Standard techniques to identify and determine the antibiotic susceptibility of M. tuberculosis infections are insensitive and slow. More rapid PCR techniques are labor intensive and require technical sophistication. PCR inhibitors, the risk of sample cross-contamination, and the limited ability to concentrate samples also hinders PCR applicability.

The GeneXpert MTB system has been developed to overcome all of these limitations. A simple sample preparation protocol involves mixing unconcentrated sputum samples with a unique sample treatment reagent (STR), which reduces M. tuberculosis viability by 9 logs while liquefying the sputum in fifteen minutes. The sputum is then transferred to a low-cost plastic cartridge, which automatically concentrates all bacilli present in a sputum sample, removes PCR inhibitors, lyses the cells, and flushes the resulting M. tuberculosis DNA into a built-in PCR reaction tube. Nested PCR is used for maximum sensitivity, and is performed automatically using a well-established, multiplexed molecular beacon assay that detects 95% of all mutations associated with rifampin resistance. Additionally, there is no cross reaction with Mycobacteria Other Than Tuberculosis (MOTT). The assay has a sensitivity of 131 cfu/mL, and isolated and detected as few as 10 bacilli per milliliter of sputum in less than two hours. Thus, the GeneXpert is as rapid as sputum microscopy, but is more sensitive.

Presented by: Frankie Myers, Luke Lee Lab, Bioengineering

Despite a growing focus from the academic community, the field of microfluidics has yet to produce many commercial devices for point-of-care (POC) diagnostics. One of the main reasons for this is the difficulty in producing low-cost, sensitive, and portable optical detection systems. Optical detection is by far the dominant method for conventional laboratory clinical chemistry. Consequently, POC systems which utilize optical detection benefit from the wealth of assay techniques and labeling chemistries that have been developed. However, conventional optical instrumentation is costly, requires careful alignment, and generally does not translate well to POC diagnostic devices. Furthermore, for a variety of reasons the sensitivity of many optical detection techniques suffers at smaller geometries. At this talk, I will survey a variety of optical measurement techniques including absorption spectroscopy, fluorescence, chemiluminescence, interferometry, surface plasmon resonance, and surface-enhanced Raman spectroscopy. Throughout, I will discuss recent innovations which make these techniques more practical for use in POC diagnostics, and I will discuss the relative advantages and disadvantages of each. I will highlight several examples, both from academia and industry, of microfluidic diagnostic systems which demonstrate practical integration of sample preparation, analyte enrichment, and optical detection.

Our kickoff meeting will be held in 340 Hearst Memorial Mining Building. Pizza and drinks will be provided!

Featured Presentation:
CMOS Based Fully Integrated Assay Platform for Point-of-Care Application in the Developing World
Octavian Florescu, Electrical Engineering, Bernhard Boser Lab

Point-of-care infectious disease diagnostic devices for the developing world must be sensitive, quantitative, easy to use, inexpensive, fast and preferably re-usable. The dearth of such devices is evidence that few technologies can address these criteria simultaneously. Complementary Metal-Oxide-Semiconductor, or CMOS, is an integrated circuit technology that for decades has enabled a high level of functionality at low cost. We will present a novel assay platform that relies on magnetic bead labels, that can be manipulated and detected on-chip. With such functionality, the sample preparation front-end has been reduced to a single membrane filter for segregating the large whole blood cells from the assayable serum.