02773nas a2200265 4500008004100000022001400041245009700055210006900152260000900221300001200230490000600242520198800248100002102236700002402257700002102281700002102302700001802323700001602341700001802357700001702375700001702392700002002409700001802429856006002447 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 uhttps://www.microfluidicsciences.com/drupal/?q=node/20002745nas a2200373 4500008004100000022001400041245009900055210006900154260000900223300001100232490000600243520168200249653002301931653001601954653001501970653002101985653001202006653001902018653001002037653001102047653004202058653002602100653001502126653001602141100002102157700002202178700001702200700002102217700001702238700002002255700001802275700001802293856006002311 2012 eng d a1932-620300aIsothermal amplification using a chemical heating device for point-of-care detection of HIV-1.0 aIsothermal amplification using a chemical heating device for poi c2012 ae314320 v73 aBACKGROUND: To date, the use of traditional nucleic acid amplification tests (NAAT) for detection of HIV-1 DNA or RNA has been restricted to laboratory settings due to time, equipment, and technical expertise requirements. The availability of a rapid NAAT with applicability for resource-limited or point-of-care (POC) settings would fill a great need in HIV diagnostics, allowing for timely diagnosis or confirmation of infection status, as well as facilitating the diagnosis of acute infection, screening and evaluation of infants born to HIV-infected mothers. Isothermal amplification methods, such as reverse-transcription, loop-mediated isothermal amplification (RT-LAMP), exhibit characteristics that are ideal for POC settings, since they are typically quicker, easier to perform, and allow for integration into low-tech, portable heating devices.
METHODOLOGY/SIGNIFICANT FINDINGS: In this study, we evaluated the HIV-1 RT-LAMP assay using portable, non-instrumented nucleic acid amplification (NINA) heating devices that generate heat from the exothermic reaction of calcium oxide and water. The NINA heating devices exhibited stable temperatures throughout the amplification reaction and consistent amplification results between three separate devices and a thermalcycler. The performance of the NINA heaters was validated using whole blood specimens from HIV-1 infected patients.
CONCLUSION: The RT-LAMP isothermal amplification method used in conjunction with a chemical heating device provides a portable, rapid and robust NAAT platform that has the potential to facilitate HIV-1 testing in resource-limited settings and POC.
10aAIDS Serodiagnosis10aDNA Primers10aDNA, Viral10aEquipment Design10aHeating10aHIV Infections10aHIV-110aHumans10aNucleic Acid Amplification Techniques10aPoint-of-Care Systems10aRNA, Viral10aTemperature1 aCurtis, Kelly, A1 aRudolph, Donna, L1 aNejad, Irene1 aSingleton, Jered1 aBeddoe, Andy1 aWeigl, Bernhard1 aLaBarre, Paul1 aOwen, Michele uhttps://www.microfluidicsciences.com/drupal/?q=node/20701075nas a2200157 4500008004100000245010100041210006900142520037900211100001900590700001400609700001500623700001600638700002100654700002000675856022200695 2012 eng d00aUnited {States} {Patent}: 8282576 - {Method} and apparatus for an improved sample capture device0 aUnited States Patent 8282576 Method and apparatus for an improve3 aA body fluid sampling device is provided. A mesh may be used to guide blood or fluid to travel directly from the wound to an analyte detecting port on the cartridge. Thus the volume of blood or body fluid produced at the wound site irregardless of its droplet geometry can be reliable and substantially completely transported to the analyte detecting member for measurement.1 aMarsot, Travis1 aLum, Paul1 aAlden, Don1 aRoss, James1 aBardell, Ron, L.1 aWeigl, Bernhard uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=11&f=G&l=50&co1=AND&d=PTXT&s1=%22Bardell%3B+Ron%22.INNM.&OS=IN/%22Bardell;+Ron%22&RS=IN/%22Bardell;+Ron%2202265nas a2200313 4500008004100000022001400041245006000055210005700115260001300172300001000185490001600195520138500211653001501596653002601611653001201637653001101649653002701660653002401687653001101711653001801722653001901740653001401759653002801773653003201801100002301833700002001856700001501876856006001891 2011 eng d a1879-347900aGestational diabetes screening: the low-cost algorithm.0 aGestational diabetes screening the lowcost algorithm c2011 Nov aS30-30 v115 Suppl 13 aThe American Diabetes Association has endorsed the demanding recommendation by the International Association of the Diabetes and Pregnancy Study Groups (IADPSG) that every pregnant woman should undergo the oral glucose tolerance test (OGTT) for the screening of gestational diabetes mellitus (GDM). The aim of this study was to find out if the fasting plasma glucose (FPG) and newer emerging technologies could simplify the cumbersome IADPSG algorithm. Two FPG thresholds (of the OGTT) were used to rule in and rule out GDM in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort (n = 23316) and a population at high risk for GDM (n = 10283). For the HAPO cohort and the high-risk population, respectively, FPG thresholds of: (a) ≥ 5.1 mmol/L (specificity 100%) independently ruled in GDM in 1769 (8.3%) women and 2975 (28.9%) women; and (b) ≤ 4.4 mmol/L ruled out GDM in 11526 (49.4%) women (84.1% sensitivity) and 2228 (21.7%) women (95.4% sensitivity). Use of the FPG independently could have avoided 13295 (57.0%) and 5203 (50.6%) OGTTs in the 2 groups. The initial FPG-by significantly reducing the number of cumbersome OGTTs needed-can make the IADPSG recommendations more acceptable worldwide. The number of GDM women missed is population dependent. For low-resource countries, alternative newer and cheaper tests in development hold an exciting future.
10aAlgorithms10aDiabetes, Gestational10aFasting10aFemale10aGlucose Tolerance Test10aGuidelines as Topic10aHumans10aHyperglycemia10aMass Screening10aPregnancy10aPregnancy Complications10aSensitivity and Specificity1 aAgarwal, Mukesh, M1 aWeigl, Bernhard1 aHod, Moshe uhttps://www.microfluidicsciences.com/drupal/?q=node/20801786nas a2200169 4500008004100000022001400041245008200055210006900137260001600206490000900222520124900231100001801480700001701498700002101515700002001536856006001556 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 aMany 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 uhttps://www.microfluidicsciences.com/drupal/?q=node/21003020nas a2200313 4500008004100000022001400041245015500055210006900210260000900279300001100288490000600299520199700305653002502302653001602327653002002343653003602363653004202399653002602441653002402467100001802491700002402509700001702533700001902550700001902569700002102588700001702609700002002626856006002646 2011 eng d a1932-620300aA simple, inexpensive device for nucleic acid amplification without electricity-toward instrument-free molecular diagnostics in low-resource settings.0 asimple inexpensive device for nucleic acid amplification without c2011 ae197380 v63 aBACKGROUND: Molecular assays targeted to nucleic acid (NA) markers are becoming increasingly important to medical diagnostics. However, these are typically confined to wealthy, developed countries; or, to the national reference laboratories of developing-world countries. There are many infectious diseases that are endemic in low-resource settings (LRS) where the lack of simple, instrument-free, NA diagnostic tests is a critical barrier to timely treatment. One of the primary barriers to the practicality and availability of NA assays in LRS has been the complexity and power requirements of polymerase chain reaction (PCR) instrumentation (another is sample preparation).
METHODOLOGY/PRINCIPAL FINDINGS: In this article, we investigate the hypothesis that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays. We assess the heater's equivalence to commercially available PCR instruments through the characterization of the temperature profiles produced, and a minimal method comparison. Versions of the prototype for several different isothermal techniques are presented.
CONCLUSIONS/SIGNIFICANCE: We demonstrate that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays, and that the results of those assays are not significantly different from ones incubated in parallel in commercially available PCR instruments. These results clearly suggest the potential of the non-instrumented nucleic acid amplification (NINA) heater for molecular diagnostics in LRS. When combined with other innovations in development that eliminate power requirements for sample preparation, cold reagent storage, and readout, the NINA heater will comprise part of a kit that should enable electricity-free NA testing for many important analytes.
10aDeveloping Countries10aElectricity10aHot Temperature10aMolecular Diagnostic Techniques10aNucleic Acid Amplification Techniques10aPlasmodium falciparum10aReference Standards1 aLaBarre, Paul1 aHawkins, Kenneth, R1 aGerlach, Jay1 aWilmoth, Jared1 aBeddoe, Andrew1 aSingleton, Jered1 aBoyle, David1 aWeigl, Bernhard uhttps://www.microfluidicsciences.com/drupal/?q=node/20902409nas a2200277 4500008004100000022001400041245012900055210006900184260000900253300001100262490000900273520153100282653001901813653001201832653001101844653002401855653003601879653004201915100001801957700001701975700001901992700001902011700002102030700002002051856006002071 2010 eng d a1557-170X00aNon-instrumented nucleic acid amplification (NINA): instrument-free molecular malaria diagnostics for low-resource settings.0 aNoninstrumented nucleic acid amplification NINA instrumentfree m c2010 a1097-90 v20103 aWe have achieved the first complete, non-instrumented nucleic acid amplification test (NAAT) using a calcium oxide heat source thermally linked to an engineered phase change material. These two components alone maintain a thermal profile suitable for the loop-mediated isothermal amplification assay. Starting with computational fluid dynamics analysis, we identified nominal geometry for the exothermic reaction chamber, phase change material chamber, thermal insulation, and packaging. Using this model, we designed and fabricated an alpha prototype assay platform. We have verified the function of this multi-pathogen-capable platform with both fluorescent and visual turbidity indications using samples spiked with malaria DNA. Both the exothermically heated platform samples and samples heated on a Perkin-Elmer GeneAmp9600 thermocycler were first incubated at 62°C for 45 minutes, then heated to 95°C to terminate enzyme activity, then analyzed. Results from the exothermically heated, non-instrumented platform were comparable to those from the thermocycler. These developments will enable point-of-care diagnostics using accurate NAATs which until now have required a well-equipped laboratory. The aim of this research is to provide pathogen detection with NAAT-level sensitivity in low-resource settings where assays such as immunochromatographic strip tests are successfully used but where there is no access to the infrastructure and logistics required to operate and maintain instrument-based diagnostics.
10aDNA, Protozoan10aHeating10aHumans10aMalaria, Falciparum10aMolecular Diagnostic Techniques10aNucleic Acid Amplification Techniques1 aLaBarre, Paul1 aGerlach, Jay1 aWilmoth, Jared1 aBeddoe, Andrew1 aSingleton, Jered1 aWeigl, Bernhard uhttps://www.microfluidicsciences.com/drupal/?q=node/21503950nas a2200493 4500008004100000022001400041245013700055210006900192260001300261300001100274490000600285520248600291653001002777653002402787653003902811653001002850653002802860653001502888653001102903653001102914653001902925653001602944653003002960653003002990653001403020653002603034653003203060653003003092653003103122100001803153700002103171700001803192700001803210700002103228700001903249700002003268700001903288700001903307700001303326700001503339700001903354700002303373856006003396 2008 eng d a1474-548800aA new HPV-DNA test for cervical-cancer screening in developing regions: a cross-sectional study of clinical accuracy in rural China.0 anew HPVDNA test for cervicalcancer screening in developing regio c2008 Oct a929-360 v93 aBACKGROUND: A new test (careHPV; QIAGEN, Gaithersburg, MD, USA) has been developed to detect 14 high-risk types of carcinogenic human papillomavirus (HPV) in about 2.5 h, to screen women in developing regions for cervical intraepithelial neoplasia (CIN). We did a cross-sectional study to assess the clinical accuracy of careHPV as a rapid screening test in two county hospitals in rural China.
METHODS: From May 10 to June 15, 2007, the careHPV test was done locally by use of self-obtained vaginal and provider-obtained cervical specimens from a screening population-based set of 2530 women aged 30 to 54 years in Shanxi province, China. All women were assessed by visual inspection with acetic acid (VIA), Digene High-Risk HPV HC2 DNA Test (HC2), liquid-based cytology, and colposcopy with directed biopsy and endocervical curettage as necessary. In 2388 women with complete data, 441 women with negative colposcopy, but unsatisfactory or abnormal cytology or who were positive on HC2 or the new careHPV test, were recalled for a second colposcopy, four-quadrant cervical biopsies, and endocervical curettage. An absence of independence between the tests was not adjusted for and the Bonferroni correction was used for multiple comparisons.
FINDINGS: Complete data were available for 2388 (94.4%) women. 70 women had CIN2+ (moderate or severe CIN or cancer), of whom 23 had CIN3+. By use of CIN2+ as the reference standard and area-under-the-curve analysis with a two-sided alpha error level of 0.0083, the sensitivities and specificities of the careHPV test for a cut-off ratio cut-point of 0.5 relative light units, were 90.0% (95% CI 83.0-97.0) and 84.2% (82.7-85.7), respectively, on cervical specimens, and 81.4% (72.3-90.5) and 82.4% (80.8-83.9), respectively, on vaginal specimens (areas under the curve not significantly different, p=0.0596), compared with 41.4% (29.9-53.0) and 94.5% (93.6-95.4) for VIA (areas under the curve significantly different, p=0.0001 and p=0.0031, for cervical and vaginal-specimen comparisons for the careHPV test, respectively). The sensitivity and specificity of HC2 for cervical specimens were 97.1% (93.2-100) and 85.6% (84.2-87.1), respectively (areas under the curve not significantly different from the careHPV test on cervical specimens, p=0.0163).
INTERPRETATION: The careHPV test is promising as a primary screening method for cervical-cancer prevention in low-resource regions.
10aAdult10aAlphapapillomavirus10aCervical Intraepithelial Neoplasia10aChina10aCross-Sectional Studies10aDNA, Viral10aFemale10aHumans10aMass Screening10aMiddle Aged10aPapillomavirus Infections10aPredictive Value of Tests10aROC Curve10aRural Health Services10aSensitivity and Specificity10aTumor Markers, Biological10aUterine Cervical Neoplasms1 aQiao, You-Lin1 aSellors, John, W1 aEder, Paul, S1 aBao, Yan-Ping1 aLim, Jeanette, M1 aZhao, Fang-Hui1 aWeigl, Bernhard1 aZhang, Wen-Hua1 aPeck, Roger, B1 aLi, Ling1 aChen, Feng1 aPan, Qing-Jing1 aLorincz, Attila, T uhttps://www.microfluidicsciences.com/drupal/?q=node/21901092nas a2200193 4500008004100000022001400041245012000055210006900175260001300244300000900257490000600266520046500272100002000737700001800757700002100775700002200796700002000818856006000838 2008 ENG d a1533-029X00aThe NIBIB Point of Care Technologies Research Network Center Themes and Opportunities for Exploratory POC Projects.0 aNIBIB Point of Care Technologies Research Network Center Themes c2008 Mar a1-410 v73 aThis article describes the new National Institute of Biomedical Imaging and Bioengineering Point-of-Care (POC) Technologies Research Network and its 4 Centers. The goal is to build expertise in development of integrated systems that address unmet POC testing clinical needs. Centers will work individually and also collectively as part of the national network to coordinate development, clinical evaluation, and reduction to practice of new POC devices.
1 aKost, Gerald, J1 aKorte, Brenda1 aBeyette, Fred, R1 aGaydos, Charlotte1 aWeigl, Bernhard uhttps://www.microfluidicsciences.com/drupal/?q=node/22001794nas a2200217 4500008004100000022001400041245008500055210006900140260001300209300001400222490000600236520111400242653004101356653002501397653001801422100002001440700002101460700001801481700001701499856006001516 2008 eng d a1473-019700aTowards non- and minimally instrumented, microfluidics-based diagnostic devices.0 aTowards non and minimally instrumented microfluidicsbased diagno c2008 Dec a1999-20140 v83 aIn many health care settings, it is uneconomical, impractical, or unaffordable to maintain and access a fully equipped diagnostics laboratory. Examples include home health care, developing-country health care, and emergency situations in which first responders are dealing with pandemics or biowarfare agent release. In those settings, fully disposable diagnostic devices that require no instrument support, reagent, or significant training are well suited. Although the only such technology to have found widespread adoption so far is the immunochromatographic rapid assay strip test, microfluidics holds promise to expand the range of assay technologies that can be performed in formats similar to that of a strip test. In this paper, we review progress toward development of disposable, low-cost, easy-to-use microfluidics-based diagnostics that require no instrument at all. We also present examples of microfluidic functional elements--including mixers, separators, and detectors--as well as complete microfluidic devices that function entirely without any moving parts and external power sources.
10aDiagnostic Techniques and Procedures10aDisposable Equipment10aMicrofluidics1 aWeigl, Bernhard1 aDomingo, Gonzalo1 aLaBarre, Paul1 aGerlach, Jay uhttps://www.microfluidicsciences.com/drupal/?q=node/21801523nas a2200157 4500008004100000245008300041210006900124520087000193100002001063700000501083700002201088700000501110700001401115700000501129856023101134 2007 eng d00aUnited {States} {Patent}: 7196842 - {Attenuating} filter for ultraviolet light0 aUnited States Patent 7196842 Attenuating filter for ultraviolet 3 aAn attenuating filter provides a prescribed attenuation of the intensity of transmitted, short-wavelength, ultraviolet light, in particular, at wavelengths below 200 nm, that is governed by a predefinable spatial distribution of its spectral transmittance. The filter has a transparent substrate (3), e.g. fabricated from crystalline calcium fluoride. A filter coating (5) fabricated from a dielectric material that absorbs over a predefined wavelength range is applied to at least one surface (4) of the substrate. In the case of operating wavelengths of about 193 nm, the filter coating consists largely of tantalum pentoxide. Filters of the type, which may be inexpensively fabricated with high yields, are noted for their high abilities to withstand laser radiation and may be effectively antireflection coated employing simply designed antireflection coatings.1 aWeigl, Bernhard1 a1 aPaul, Hans-Jochen1 a1 aEva, Eric1 a uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=16&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%2202069nas a2200133 4500008004100000245009700041210006900138520142200207100001501629700002001644700002401664700001601688856023101704 2001 eng d00aUnited {States} {Patent}: 6221677 - {Simultaneous} particle separation and chemical reaction0 aUnited States Patent 6221677 Simultaneous particle separation an3 aThis invention provides a method and apparatus for detecting the presence of analyte particles in a sample fluid also comprising larger particles, particularly blood. It exploits diffusion to provide simultaneous filtering of the larger particles and reaction of the analyte particles. A sample stream and a reagent stream join on the upstream end of a laminar flow reaction channel and flow in adjacent laminar streams. The reagents can be in solution or immobilized on a bead. The analyte particles diffuse from the sample stream into the reagent stream, leaving behind the larger particles in the residual sample stream. In the reagent stream the analyte particles react with reagent particles and form product particles, thereby creating a product stream. At the downstream end of the reaction channel, the residual sample stream and the product stream are divided. The product particles are then detected, preferably optically, in the product stream. Prior to detection, the product stream can undergo further filtering or separation, or can join a second reagent stream to form secondary product particles. This apparatus and method can be used to implement competitive immunoassays or sandwich immunoassays using enzymatically or fluorescently labeled immunoreagents. The apparatus and method can also be used to synthesize products, in which case two reagent streams join in the laminar flow reaction channel.1 aWu, Caicai1 aWeigl, Bernhard1 aKenny, Margaret, A.1 aYager, Paul uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=29&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%2201275nas a2200121 4500008004100000245013000041210006900171260000800240520064900248100002000897700000500917856023100922 2001 eng d00aUnited {States} {Patent}: 6294296 - {Method} and device for mutually aligning a mask pattern formed in a mask and a substrate0 aUnited States Patent 6294296 Method and device for mutually alig csep3 aIn a method for mutually aligning a mask pattern formed in a mask 1 and a substrate 2, on which the mask pattern is to be imaged, by using setting marks 12a, 12b and 13a or 13b in the mask 1 and in the substrate 2, the alignment is performed with the aid of an imaging system and a light beam with polarized light 9. A phase shift for the first diffraction orders 20 is undertaken in the beam path 9a, 9b. Higher diffraction orders 21 and unwanted light are filtered out after the phase shift, and after the filtering out the light beams of the first diffraction orders 20 are detected, and the result is evaluated for the purpose of alignment.1 aWeigl, Bernhard1 a uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=28&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%2202089nas a2200145 4500008004100000245009700041210006900138260000800207520142200215100001501637700002001652700002401672700001601696856023101712 2001 eng d00aUnited {States} {Patent}: 6297061 - {Simultaneous} particle separation and chemical reaction0 aUnited States Patent 6297061 Simultaneous particle separation an coct3 aThis invention provides a method and apparatus for detecting the presence of analyte particles in a sample fluid also comprising larger particles, particularly blood. It exploits diffusion to provide simultaneous filtering of the larger particles and reaction of the analyte particles. A sample stream and a reagent stream join on the upstream end of a laminar flow reaction channel and flow in adjacent laminar streams. The reagents can be in solution or immobilized on a bead. The analyte particles diffuse from the sample stream into the reagent stream, leaving behind the larger particles in the residual sample stream. In the reagent stream the analyte particles react with reagent particles and form product particles, thereby creating a product stream. At the downstream end of the reaction channel, the residual sample stream and the product stream are divided. The product particles are then detected, preferably optically, in the product stream. Prior to detection, the product stream can undergo further filtering or separation, or can join a second reagent stream to form secondary product particles. This apparatus and method can be used to implement competitive immunoassays or sandwich immunoassays using enzymatically or fluorescently labeled immunoreagents. The apparatus and method can also be used to synthesize products, in which case two reagent streams join in the laminar flow reaction channel.1 aWu, Caicai1 aWeigl, Bernhard1 aKenny, Margaret, A.1 aYager, Paul uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=27&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%2202256nas a2200133 4500008004100000245009600041210006900137260000800206520161100214100002001825700002201845700002401867856023101891 2000 eng d00aUnited {States} {Patent}: 6136272 - {Device} for rapidly joining and splitting fluid layers0 aUnited States Patent 6136272 Device for rapidly joining and spli coct3 aA device and method for introducing a second laminar fluid layer to, or removing a second laminar fluid layer from, a first laminar fluid layer are provided. Each laminar fluid layer can contain two or more side by side laminar streams. The device includes a main flow channel, and at least one tributary channel in fluid connection with a bridge channel which is in fluid connection with main flow channel. The device can be formed in a single piece of material, which can be optically transparent. Optionally, the channels can be formed in a first plate, the first and optionally the second surfaces of which are sealed to a second and optionally a third plate. The second and third plates can be optically transparent to allow for optical detection and analysis. A first laminar fluid layer is introduced into the main flow channel. If a second laminar fluid layer is to be added to the first laminar fluid layer, then the former is introduced into the tributary channel, from whence it flows into the bridge channel and then into the main flow channel, where it flows below the first laminar fluid layer and diffusionally mixes with it. Preferably, the width of the main flow channel is relatively small, so that particles in an added second laminar fluid layer diffusionally mix into the first laminar fluid layer rapidly. If a second laminar fluid layer is to be removed from a first laminar fluid layer, then the latter is split into two portions: one portion continues flowing down the main flow channel and one portion flows into the bridge channel from whence it flows into the tributary channel.1 aWeigl, Bernhard1 aZebert, Diane, M.1 aKenny, Margaret, A. uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=32&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%2202085nas a2200133 4500008004100000245013400041210006900175260000800244520141100252100002001663700001601683700002101699856023101720 2000 eng d00aUnited {States} {Patent}: 6159739 - {Device} and method for 3-dimensional alignment of particles in microfabricated flow channels0 aUnited States Patent 6159739 Device and method for 3dimensional cdec3 aThe present invention provides a sheath flow module made from a first plate of material having formed therein a laminar fluid flow channel; at least two inlets, each inlet joining the laminar flow channel at a junction, the first inlet junction being wider than the second inlet junction, and an outlet from the flow channel. A second plate, e.g. a transparent cover plate, seals the module and allows for optical measurements. A first inlet allows for introduction of a first fluid into the flow channel. The first fluid is the sheath fluid. A second inlet allows for introduction of a second fluid into the sheath fluid while it is flowing through the flow channel. The second fluid is the center fluid. Because the second inlet junction is narrower than the first inlet junction, the center fluid becomes surrounded on both sides by the sheath fluid. After all fluids have been introduced and sheath flow has been achieved, the depth of the flow channel can be decreased, leading to vertical hydrodynamic focusing. Optionally, the width of the flow channel can be decreased, leading to horizontal hydrodynamic focusing. The decrease in depth and width can be gradual or abrupt. The device of the present invention can function in two modes, the sheath flow mode and the particle injector mode, depending on the relative densities of the sheath fluid, the center fluid, and any particles in either fluid.1 aWeigl, Bernhard1 aYager, Paul1 aBrody, James, P. uhttp://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=31&f=G&l=50&co1=AND&d=PTXT&s1=%22Weigl%3B+Bernhard%22.INNM.&OS=IN/%22Weigl;+Bernhard%22&RS=IN/%22Weigl;+Bernhard%22