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Khalid N, Kobayashi I, Nakajima M. Recent lab-on-chip developments for novel drug discovery. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2017; 9. [DOI: 10.1002/wsbm.1381] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 12/11/2016] [Accepted: 12/20/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Nauman Khalid
- School of Food and Agricultural Sciences; University of Management and Technology; Lahore Pakistan
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences; Deakin University; Waurn Ponds Australia
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Japan
| | - Isao Kobayashi
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Japan
- Food Research Institute; NARO; Tsukuba Japan
| | - Mitsutoshi Nakajima
- Graduate School of Life and Environmental Sciences; University of Tsukuba; Tsukuba Japan
- Food Research Institute; NARO; Tsukuba Japan
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Eribol P, Uguz AK, Ulgen KO. Screening applications in drug discovery based on microfluidic technology. BIOMICROFLUIDICS 2016; 10:011502. [PMID: 26865904 PMCID: PMC4733079 DOI: 10.1063/1.4940886] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 01/14/2016] [Indexed: 05/03/2023]
Abstract
Microfluidics has been the focus of interest for the last two decades for all the advantages such as low chemical consumption, reduced analysis time, high throughput, better control of mass and heat transfer, downsizing a bench-top laboratory to a chip, i.e., lab-on-a-chip, and many others it has offered. Microfluidic technology quickly found applications in the pharmaceutical industry, which demands working with leading edge scientific and technological breakthroughs, as drug screening and commercialization are very long and expensive processes and require many tests due to unpredictable results. This review paper is on drug candidate screening methods with microfluidic technology and focuses specifically on fabrication techniques and materials for the microchip, types of flow such as continuous or discrete and their advantages, determination of kinetic parameters and their comparison with conventional systems, assessment of toxicities and cytotoxicities, concentration generations for high throughput, and the computational methods that were employed. An important conclusion of this review is that even though microfluidic technology has been in this field for around 20 years there is still room for research and development, as this cutting edge technology requires ingenuity to design and find solutions for each individual case. Recent extensions of these microsystems are microengineered organs-on-chips and organ arrays.
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Affiliation(s)
- P Eribol
- Department of Chemical Engineering, Boğaziçi University , 34342 Bebek, Istanbul, Turkey
| | - A K Uguz
- Department of Chemical Engineering, Boğaziçi University , 34342 Bebek, Istanbul, Turkey
| | - K O Ulgen
- Department of Chemical Engineering, Boğaziçi University , 34342 Bebek, Istanbul, Turkey
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Luo S, Li T, Wang Q, Tian R, Liu H, Fang H, Chen F, Wang H. Development of a fusion protein SNVP as substrate for assaying multi-serotype botulinum neurotoxins. Anal Biochem 2013; 463:75-81. [PMID: 23851341 DOI: 10.1016/j.ab.2013.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 06/19/2013] [Accepted: 06/24/2013] [Indexed: 10/26/2022]
Abstract
The SNARE super family has three core members, namely SNAP-25, VAMP-2, and syntaxin. SNAP-25 is cleaved by botulinum toxins (BoNTs)/A, /C, and /E, whereas VAMP-2 is the substrate for proteolytic BoNTs/B, /D, /F, and /G. In this study, we constructed a hybrid gene encoding the fusion protein SNVP that encompasses SNAP-25 residues Met1 to Gly206 and VAMP-2 residues Met1 to Lys94. The hybrid gene was cloned in a prokaryotic vector carrying an N-terminal pelB signal sequence and overexpressed in Escherichia coli BL21(DE3) Rosetta. To easily purify the protein, 6× His double-affinity tags were designed as the linker and C terminus of the fusion protein. SNVP was purified to homogeneity by affinity chromatography on a HisTrap FF column and determined to be more than 97% pure by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. N-terminal sequencing of the purified protein showed that signal peptide was successfully removed. The fusion protein SNVP contained the protease cleavage sites of all seven serotypes of BoNTs. SNVP was also proved to be recognized and cleaved by the endopeptidase of BoNTs (BoNT/A-LC, BoNT/B-LC, BoNT/E-LC, and BoNT/G-LC). The novel fusion substrate SNVP exhibited high biological activity under the optimal conditions, suggesting its potential use as a reagent for BoNT assay.
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Affiliation(s)
- Sen Luo
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China; Department of Microbiology, An Hui Medical University, An Hui 230032, PR China
| | - Tao Li
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Qin Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Renmao Tian
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Hao Liu
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Huali Fang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Fanghong Chen
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China
| | - Hui Wang
- State Key Laboratory of Pathogens and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, PR China.
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Neethirajan S, Kobayashi I, Nakajima M, Wu D, Nandagopal S, Lin F. Microfluidics for food, agriculture and biosystems industries. LAB ON A CHIP 2011; 11:1574-86. [PMID: 21431239 DOI: 10.1039/c0lc00230e] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Microfluidics, a rapidly emerging enabling technology has the potential to revolutionize food, agriculture and biosystems industries. Examples of potential applications of microfluidics in food industry include nano-particle encapsulation of fish oil, monitoring pathogens and toxins in food and water supplies, micro-nano-filtration for improving food quality, detection of antibiotics in dairy food products, and generation of novel food structures. In addition, microfluidics enables applications in agriculture and animal sciences such as nutrients monitoring and plant cells sorting for improving crop quality and production, effective delivery of biopesticides, simplified in vitro fertilization for animal breeding, animal health monitoring, vaccination and therapeutics. Lastly, microfluidics provides new approaches for bioenergy research. This paper synthesizes information of selected microfluidics-based applications for food, agriculture and biosystems industries.
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Affiliation(s)
- Suresh Neethirajan
- Biological and Nanoscale Systems Group, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
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Sapsford KE, Granek J, Deschamps JR, Boeneman K, Blanco-Canosa JB, Dawson PE, Susumu K, Stewart MH, Medintz IL. Monitoring botulinum neurotoxin a activity with peptide-functionalized quantum dot resonance energy transfer sensors. ACS NANO 2011; 5:2687-2699. [PMID: 21361387 DOI: 10.1021/nn102997b] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Botulinum neurotoxins (BoNTs) are extremely potent bacterial toxins that contaminate food supplies along with having a high potential for exploitation as bioterrorism agents. There is a continuing need to rapidly and sensitively detect exposure to these toxins and to verify their active state, as the latter directly affects diagnosis and helps provide effective treatments. We investigate the use of semiconductor quantum dot (QD)-peptide Förster resonance energy transfer (FRET) assemblies to monitor the activity of the BoNT serotype A light chain protease (LcA). A modular LcA peptide substrate was designed and optimized to contain a central LcA recognition/cleavage region, a unique residue to allow labeling with a Cy3 acceptor dye, an extended linker-spacer sequence, and a terminal oligohistidine that allows for final ratiometric peptide-QD-self-assembly. A number of different QD materials displaying charged or PEGylated surface-coatings were evaluated for their ability to self-assemble dye-labeled LcA peptide substrates by monitoring FRET interactions. Proteolytic assays were performed utilizing either a direct peptide-on-QD format or alternatively an indirect pre-exposure of peptide to LcA prior to QD assembly. Variable activities were obtained depending on QD materials and formats used with the most sensitive pre-exposure assay result demonstrating a 350 pM LcA limit of detection. Modeling the various QD-peptide sensor constructs provided insight into how the resulting assembly architecture influenced LcA recognition interactions and subsequent activity. These results also highlight the unique roles that both peptide design and QD features, especially surface-capping agents, contribute to overall sensor activity.
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Affiliation(s)
- Kim E Sapsford
- Division of Biology, Office of Science and Engineering Laboratories, U.S. Food and Drug Administration, Silver Spring, Maryland 20993, USA.
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Frisk ML, Lin G, Johnson EA, Beebe DJ. Synaptotagmin II peptide-bead conjugate for botulinum toxin enrichment and detection in microchannels. Biosens Bioelectron 2011; 26:1929-35. [DOI: 10.1016/j.bios.2010.06.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Revised: 05/27/2010] [Accepted: 06/23/2010] [Indexed: 11/29/2022]
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Hakami RM, Ruthel G, Stahl AM, Bavari S. Gaining ground: assays for therapeutics against botulinum neurotoxin. Trends Microbiol 2010; 18:164-72. [DOI: 10.1016/j.tim.2010.02.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Revised: 01/20/2010] [Accepted: 02/01/2010] [Indexed: 11/15/2022]
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Abstract
Sensitive and rapid detection of botulinum neurotoxins (BoNTs), the most poisonous substances known to date, is essential for studies of medical applications of BoNTs and detection of poisoned food, as well as for response to potential bioterrorist threats. Currently, the most common method of BoNT detection is the mouse bioassay. While this assay is sensitive, it is slow, quite expensive, has limited throughput and requires sacrificing animals. Herein, we discuss and compare recently developed alternative in vitro detection methods and assess their ability to supplement or replace the mouse bioassay in the analysis of complex matrix samples.
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Affiliation(s)
- Petr Čapek
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA;
| | - Tobin J. Dickerson
- Department of Chemistry and Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-858-784-2522; Fax: +1-858-784-2590
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Čapek P, Dickerson TJ. Sensing the deadliest toxin: technologies for botulinum neurotoxin detection. Toxins (Basel) 2010; 2:24-53. [PMID: 22069545 PMCID: PMC3206617 DOI: 10.3390/toxins2020024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 12/17/2009] [Accepted: 12/22/2009] [Indexed: 11/16/2022] Open
Abstract
Sensitive and rapid detection of botulinum neurotoxins (BoNTs), the most poisonous substances known to date, is essential for studies of medical applications of BoNTs and detection of poisoned food, as well as for response to potential bioterrorist threats. Currently, the most common method of BoNT detection is the mouse bioassay. While this assay is sensitive, it is slow, quite expensive, has limited throughput and requires sacrificing animals. Herein, we discuss and compare recently developed alternative in vitro detection methods and assess their ability to supplement or replace the mouse bioassay in the analysis of complex matrix samples.
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Affiliation(s)
- Petr Čapek
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA;
| | - Tobin J. Dickerson
- Department of Chemistry and Worm Institute for Research and Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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Sun S, Ossandon M, Kostov Y, Rasooly A. Lab-on-a-chip for botulinum neurotoxin a (BoNT-A) activity analysis. LAB ON A CHIP 2009; 9:3275-81. [PMID: 19865736 PMCID: PMC2849933 DOI: 10.1039/b912097a] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
A Lab-on-a-chip (LOC) was designed, fabricated and tested for the in vitro detection of botulinum neurotoxin serotype A (BoNT-A) activity using an assay that measures cleavage of a fluorophore-tagged peptide substrate specific for BoNT-A (SNAP-25) by the toxin light chain (LcA). LcA cleavage was detected by Förster Resonance Energy Transfer (FRET) fluorescence. FRET fluorescence was measured by a newly developed portable charge-coupled device (CCD) fluorescent detector equipped with multi-wavelength light-emitting diodes (LED) illumination. An eight V-junction microchannel device for BoNTs activity assays was constructed using Laminated Object Manufacturing (LOM) technology. The six-layer device was fabricated with a Poly(methyl methacrylate (PMMA) core and five polycarbonate (PC) layers micromachined by CO2 laser. The LOC is operated by syringe and is equipped with reagents, sample wells, reaction wells, diffusion traps (to avoid cross contamination among channels) and waste reservoirs. The system was detected LcA at concentrations as low as 0.5 nM, which is the reported sensitivity of the SNAP-25 in vitro cleavage assay. Combined with our CCD detector, the simple point of care system enables the detection of BoNTs activity and may be useful for the performance of other complex medical assays without a laboratory. This approach may realize the potential to enhance the quality of health care delivery for underserved populations.
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Affiliation(s)
- Steven Sun
- Division of Biology, Office of Science and Engineering Laboratories, FDA, NIH/NCI, Silver Spring, MD, 20993, USA6130 Executive Blvd. EPN, Room 6035A Rockville, 20852; Fax: (+301) 402-7819; Tel: (+301) 402-4185
- Center for Advanced Sensor Technology, University of Maryland Baltimore County, MD, 21250
| | - Miguel Ossandon
- Cancer Diagnosis Program, National Cancer Institute, Rockville, MD, 20892
| | - Yordan Kostov
- Center for Advanced Sensor Technology, University of Maryland Baltimore County, MD, 21250
| | - Avraham Rasooly
- Division of Biology, Office of Science and Engineering Laboratories, FDA, NIH/NCI, Silver Spring, MD, 20993, USA6130 Executive Blvd. EPN, Room 6035A Rockville, 20852; Fax: (+301) 402-7819; Tel: (+301) 402-4185
- Cancer Diagnosis Program, National Cancer Institute, Rockville, MD, 20892
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Frisk ML, Tepp WH, Johnson EA, Beebe DJ. Self-assembled peptide monolayers as a toxin sensing mechanism within arrayed microchannels. Anal Chem 2009; 81:2760-7. [PMID: 19253949 PMCID: PMC2760437 DOI: 10.1021/ac802707u] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A sensor for the lethal bacterial enzyme, botulinum neurotoxin type A (BoNT/A), was developed using self-assembled monolayers (SAMs). SAMs consisting of an immobilized synthetic peptide that mimicked the toxin's in vivo SNAP-25 protein substrate were formed on Au and interfaced with arrayed microfluidic channels. Efforts to optimize SAM composition and assay conditions for greatest reaction efficiency and sensitivity are described in detail. Channel design provided facile fluid manipulation, sample incubation, analyte concentration, and fluorescence detection all within a single microfluidic channel, thus avoiding sample transfer and loss. Peptide SAMs were exposed to varying concentrations of BoNT/A or its catalytic light chain (ALC), resulting in enzymatic cleavage of the peptide substrate from the surface. Fluorescence detection was achieved down to 20 pg/mL ALC and 3 pg/mL BoNT/A in 3 h. Toxin sensing was also accomplished in vegetable soup, demonstrating practicality of the method. The modular design of this microfluidic SAM platform allows for extension to sensing other toxins that operate via enzymatic cleavage, such as the remaining BoNT serotypes B-G, anthrax, and tetanus toxin.
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Affiliation(s)
- Megan L. Frisk
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - William H. Tepp
- Department of Food Microbiology and Toxicology, Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706
| | - Eric A. Johnson
- Department of Food Microbiology and Toxicology, Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706
| | - David J. Beebe
- Department of Biomedical Engineering, University of Wisconsin, Madison, Wisconsin 53706
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Wang Z, King TL, Branagan SP, Bohn PW. Enzymatic activity of surface-immobilized horseradish peroxidase confined to micrometer- to nanometer-scale structures in nanocapillary array membranes. Analyst 2009; 134:851-9. [DOI: 10.1039/b815590a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Frisk ML, Berthier E, Tepp WH, Johnson EA, Beebe DJ. Bead-based microfluidic toxin sensor integrating evaporative signal amplification. LAB ON A CHIP 2008; 8:1793-800. [PMID: 18941677 DOI: 10.1039/b811075a] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We have devised a microfluidic platform that incorporates substrate-laden silica beads for sensing the proteolytic activity of botulinum neurotoxin type A (BoNT/A)-one of the most poisonous substances known and a significant biological threat. The sensor relies on toxin-mediated cleavage of a fluorophore-tagged peptide substrate specific for only BoNT/A. Peptide immobilized on beads is recognized and cleaved by the toxin, releasing fluorescent fragments into solution that can be concentrated at an isolated port via evaporation and detected using microscopy. Evaporative concentration in combination with a specific channel geometry provides up to a 3-fold signal amplification in 35 min, allowing for detection of low levels of fluorophore-labeled peptide-a task not easily accomplished using traditional channel designs. Our bead-based microfluidic platform can sense BoNT/A down to 10 pg of toxin per mL buffer solution in 3.5 h and can be adapted to sensing other toxins that operate via enzymatic cleavage of a known substrate.
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Affiliation(s)
- Megan L Frisk
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA
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A fluorescence detection platform using spatial electroluminescent excitation for measuring botulinum neurotoxin A activity. Biosens Bioelectron 2008; 24:618-25. [PMID: 18644709 DOI: 10.1016/j.bios.2008.06.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Revised: 04/23/2008] [Accepted: 06/04/2008] [Indexed: 11/22/2022]
Abstract
Current biodetection illumination technologies (laser, LED, tungsten lamp, etc.) are based on spot illumination with additional optics required when spatial excitation is required. Herein we describe a new approach of spatial illumination based on electroluminescence (EL) semiconductor strips available in several wavelengths, greatly simplifying the biosensor design by eliminating the need for additional optics. This work combines EL excitation with charge-coupled device (CCD) based detection (EL-CCD detector) of fluorescence for developing a simple portable detector for botulinum neurotoxin A (BoTN-A) activity analysis. A Förster Resonance Energy Transfer (FRET) activity assay for BoTN-A was used to both characterize and optimize the EL-CCD detector. The system consists of two modules: (1) the detection module which houses the CCD camera and emission filters, and (2) the excitation and sample module, containing the EL strip, the excitation filter and the 9-well sample chip. The FRET activity assay used in this study utilized a FITC/DABCYL-SNAP-25 peptide substrate in which cleavage of the substrate by BoTN-A, or its light chain derivative (LcA), produced an increase in fluorescence emission. EL-CCD detector measured limits of detection (LODs) were similar to those measured using a standard fluorescent plate reader with valves between 0.625 and 1.25 nM (31-62 ng/ml) for LcA and 0.313 nM (45 ng/ml) for the full toxin, BoTN-A. As far as the authors are aware this is the first demonstration of phosphor-based EL strips being used for the spatial illumination/excitation of a surface, coupled with CCD for point of care detection.
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Hines HB, Kim AD, Stafford RG, Badie SS, Brueggeman EE, Newman DJ, Schmidt JJ. Use of a recombinant fluorescent substrate with cleavage sites for all botulinum neurotoxins in high-throughput screening of natural product extracts for inhibitors of serotypes A, B, and E. Appl Environ Microbiol 2008; 74:653-9. [PMID: 18083881 PMCID: PMC2227718 DOI: 10.1128/aem.01690-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Accepted: 11/26/2007] [Indexed: 11/20/2022] Open
Abstract
The seven serotypes of botulinum neurotoxin (BoNTs) are zinc metalloproteases that cleave and inactivate proteins critical for neurotransmission. The synaptosomal protein of 25 kDa (SNAP-25) is cleaved by BoNTs A, C, and E, while vesicle-associated membrane protein (VAMP) is the substrate for BoNTs B, D, F, and G. BoNTs not only are medically useful drugs but also are potential bioterrorist and biowarfare threat agents. Because BoNT protease activity is required for toxicity, inhibitors of that activity might be effective for antibotulinum therapy. To expedite inhibitor discovery, we constructed a hybrid gene encoding (from the N terminus to the C terminus, with respect to the expressed product) green fluorescent protein, then a SNAP-25 fragment encompassing residues Met-127 to Gly-206, and then VAMP residues Met-1 to Lys-94. Cysteine was added as the C terminus. The expressed product, which contained the protease cleavage sites for all seven botulinum serotypes, was purified and coupled covalently through the C-terminal sulfhydryl group to maleimide-activated 96-well plates. The substrate was readily cleaved by BoNTs A, B, D, E, and F. Using this assay and an automated 96-well pipettor, we screened 528 natural product extracts for inhibitors of BoNT A, B, and E protease activities. Serotype-specific inhibition was found in 30 extracts, while 5 others inhibited two serotypes.
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Affiliation(s)
- Harry B Hines
- Department of Cell Biology and Biochemistry, Integrated Toxicology Division, USAMRIID, Frederick, MD 21702-5011, USA
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