02768nas a2200265 4500008004100000022001400041245009700055210006900152260000900221300001200230490000600242520198800248100002102236700002402257700002102281700002102302700001802323700001602341700001802357700001702375700001702392700002002409700001802429856005502447 2014 eng d a1932-620300aElectricity-free amplification and detection for molecular point-of-care diagnosis of HIV-1.0 aElectricityfree amplification and detection for molecular pointo c2014 ae1136930 v93 a

In resource-limited settings, the lack of decentralized molecular diagnostic testing and sparse access to centralized medical facilities can present a critical barrier to timely diagnosis, treatment, and subsequent control and elimination of infectious diseases. Isothermal nucleic acid amplification methods, including reverse transcription loop-mediated isothermal amplification (RT-LAMP), are well-suited for decentralized point-of-care molecular testing in minimal infrastructure laboratories since they significantly reduce the complexity of equipment and power requirements. Despite reduced complexity, however, there is still a need for a constant heat source to enable isothermal nucleic acid amplification. This requirement poses significant challenges for laboratories in developing countries where electricity is often unreliable or unavailable. To address this need, we previously developed a low-cost, electricity-free heater using an exothermic reaction thermally coupled with a phase change material. This heater achieved acceptable performance, but exhibited considerable variability. Furthermore, as an enabling technology, the heater was an incomplete diagnostic solution. Here we describe a more precise, affordable, and robust heater design with thermal standard deviation <0.5°C at operating temperature, a cost of approximately US$.06 per test for heater reaction materials, and an ambient temperature operating range from 16°C to 30°C. We also pair the heater with nucleic acid lateral flow (NALF)-detection for a visual readout. To further illustrate the utility of the electricity-free heater and NALF-detection platform, we demonstrate sensitive and repeatable detection of HIV-1 with a ß-actin positive internal amplification control from processed sample to result in less than 80 minutes. Together, these elements are building blocks for an electricity-free platform capable of isothermal amplification and detection of a variety of pathogens.

1 aSingleton, Jered1 aOsborn, Jennifer, L1 aLillis, Lorraine1 aHawkins, Kenneth1 aGuelig, Dylan1 aPrice, Will1 aJohns, Rachel1 aEbels, Kelly1 aBoyle, David1 aWeigl, Bernhard1 aLaBarre, Paul uhttp://microfluidicsciences.com/drupal/?q=node/20003619nas a2200493 4500008004100000022001400041245009300055210006900148260000900217300001100226490000600237520221300243653002502456653002802481653002502509653002002534653003002554653001102584653002502595653001802620653002302638653001002661653002602671653001202697100002102709700001802730700001902748700002002767700001802787700002102805700002102826700002002847700002102867700002202888700002202910700002402932700002002956700001702976700001902993700001803012700001703030700002303047856005503070 2013 eng d a1932-620300aField evaluation of a prototype paper-based point-of-care fingerstick transaminase test.0 aField evaluation of a prototype paperbased pointofcare fingersti c2013 ae756160 v83 a

Monitoring for drug-induced liver injury (DILI) via serial transaminase measurements in patients on potentially hepatotoxic medications (e.g., for HIV and tuberculosis) is routine in resource-rich nations, but often unavailable in resource-limited settings. Towards enabling universal access to affordable point-of-care (POC) screening for DILI, we have performed the first field evaluation of a paper-based, microfluidic fingerstick test for rapid, semi-quantitative, visual measurement of blood alanine aminotransferase (ALT). Our objectives were to assess operational feasibility, inter-operator variability, lot variability, device failure rate, and accuracy, to inform device modification for further field testing. The paper-based ALT test was performed at POC on fingerstick samples from 600 outpatients receiving HIV treatment in Vietnam. Results, read independently by two clinic nurses, were compared with gold-standard automated (Roche Cobas) results from venipuncture samples obtained in parallel. Two device lots were used sequentially. We demonstrated high inter-operator agreement, with 96.3% (95% C.I., 94.3-97.7%) agreement in placing visual results into clinically-defined "bins" (<3x, 3-5x, and >5x upper limit of normal), >90% agreement in validity determination, and intraclass correlation coefficient of 0.89 (95% C.I., 0.87-0.91). Lot variability was observed in % invalids due to hemolysis (21.1% for Lot 1, 1.6% for Lot 2) and correlated with lots of incorporated plasma separation membranes. Invalid rates <1% were observed for all other device controls. Overall bin placement accuracy for the two readers was 84% (84.3%/83.6%). Our findings of extremely high inter-operator agreement for visual reading-obtained in a target clinical environment, as performed by local practitioners-indicate that the device operation and reading process is feasible and reproducible. Bin placement accuracy and lot-to-lot variability data identified specific targets for device optimization and material quality control. This is the first field study performed with a patterned paper-based microfluidic device and opens the door to development of similar assays for other important analytes.

10aAlanine Transaminase10aBlood Chemical Analysis10aDeveloping Countries10aDrug Monitoring10aDrug-Induced Liver Injury10aHumans10aLiver Function Tests10aMicrofluidics10aObserver Variation10aPaper10aPoint-of-Care Systems10aVietnam1 aPollock, Nira, R1 aMcGray, Sarah1 aColby, Donn, J1 aNoubary, Farzad1 aNguyen, Huyen1 aNguyen, The, Anh1 aKhormaee, Sariah1 aJain, Sidhartha1 aHawkins, Kenneth1 aKumar, Shailendra1 aRolland, Jason, P1 aBeattie, Patrick, D1 aChau, Nguyen, V1 aQuang, Vo, M1 aBarfield, Cori1 aTietje, Kathy1 aSteele, Matt1 aWeigl, Bernhard, H uhttp://microfluidicsciences.com/drupal/?q=node/20301781nas a2200169 4500008004100000022001400041245008200055210006900137260001600206490000900222520124900231100001801480700001701498700002101515700002001536856005501556 2011 ENG d a0277-786X00aInstrument-free nucleic acid amplification assays for global health settings.0 aInstrumentfree nucleic acid amplification assays for global heal c2011 May 160 v80293 a

Many infectious diseases that affect global health are most accurately diagnosed through nucleic acid amplification and detection. However, existing nucleic acid amplification tests are too expensive and complex for most low-resource settings. The small numbers of centralized laboratories that exist in developing countries tend to be in urban areas and primarily cater to the affluent. In contrast, rural area health care facilities commonly have only basic equipment and health workers have limited training and little ability to maintain equipment and handle reagents.(1) Reliable electric power is a common infrastructure shortfall. In this paper, we discuss a practical approach to the design and development of non-instrumented molecular diagnostic tests that exploit the benefits of isothermal amplification strategies. We identify modular instrument-free technologies for sample collection, sample preparation, amplification, heating, and detection. By appropriately selecting and integrating these instrument-free modules, we envision development of an easy to use, infrastructure independent diagnostic test that will enable increased use of highly accurate molecular diagnostics at the point of care in low-resource settings.

1 aLaBarre, Paul1 aBoyle, David1 aHawkins, Kenneth1 aWeigl, Bernhard uhttp://microfluidicsciences.com/drupal/?q=node/21001426nas a2200169 4500008004100000245014600041210006900187260000800256520063200264100002400896700002400920700002000944700002000964700002000984700002101004856023101025 2006 eng d00aUnited {States} {Patent}: 7011791 - {Microfluidic} devices for rotational manipulation of the fluidic interface between multiple flow streams0 aUnited States Patent 7011791 Microfluidic devices for rotational cmar3 aMicrofluidic devices and methods are provided for enhancing detection of a diffusion pattern formed by particles diffusing between at least two fluid streams in parallel laminar flow such that an interface is formed between them by increasing the dimension of the streams in the diffusion direction. This may be accomplished by flowing the streams through a transforming turn, or by flowing the streams through a channel having diverging walls. Devices and methods are also provided for enhancing diffusion between two streams comprising changing the interface between said streams from a narrow interface to a broad interface.1 aWeigl, Bernhard, H.1 aBardell, Ronald, L.1 aKamholz, Andrew1 aMunson, Matthew1 aSchilling, Eric1 aHawkins, Kenneth uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=17&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%22