हम oligonucleotide मिलकर फ्लोरोसेंट मनकों का उपयोग कर एक नमूना के भीतर सूक्ष्मजीवों का पता लगाने के के लिए एक मल्टीप्लेक्स विधि का वर्णन. एक नमूना के भीतर सभी जीवों से Amplicon जांच युग्मित मोती के एक पैनल को संकरित है. एक Luminex या जैव Plex साधन मनका प्रकार और संकरण संकेत के लिए प्रत्येक मनका क्वेरी के लिए प्रयोग किया जाता है.
Bacterial vaginosis (BV) is a recurring polymicrobial syndrome that is characterized by a change in the “normal” microbiota from Lactobacillus-dominated to a microbiota dominated by a number of bacterial species, including Gardnerella vaginalis, Atopobium vaginae, and others1-3. This condition is associated with a range of negative health outcomes, including HIV acquisition4, and it can be difficult to manage clinically5. Furthermore, diagnosis of BV has relied on the use of Gram stains of vaginal swab smears that are scored on various numerical criteria6,7. While this diagnostic is simple, inexpensive, and well suited to resource-limited settings, it can suffer from problems related to subjective interpretations and it does not give a detailed profile of the composition of the vaginal microbiota8. Recent deep sequencing efforts have revealed a rich, diverse vaginal microbiota with clear differences between samples taken from individuals that are diagnosed with BV compared to those individuals that are considered normal9,10, which has resulted in the identification of a number of potential targets for molecular diagnosis of BV11,12. These studies have provided a wealth of useful information, but deep sequencing is not yet practical as a diagnostic method in a clinical setting. We have recently described a method for rapidly profiling the vaginal microbiota in a multiplex format using oligonucleotide-coupled fluorescent beads with detection on a Luminex platform13. This method, like current Gram stain-based methods, is rapid and simple but adds the additional advantage of exploiting molecular knowledge arising from sequencing studies in probe design. This method therefore provides a way to profile the major microorganisms that are present in a vaginal swab that can be used to diagnose BV with high specificity and sensitivity compared to Gram stain while providing additional information on species presence and abundance in a semi-quantitative and rapid manner. This multiplex method is expandable well beyond the range of current quantitative PCR assays for particular organisms, which is currently limited to 5 or 6 different assays in a single sample14. Importantly, the method is not limited to the detection of bacteria in vaginal swabs and can be easily adapted to rapidly profile nearly any microbial community of interest. For example, we have recently begun to apply this methodology to the development of diagnostic tools for use in wastewater treatment plants.
संकेत पीढ़ी की विशिष्टता के महत्व का है, आप विश्वास होना चाहिए कि संकेत मनाया वास्तव में है कि जीव से उत्पन्न amplicon का पता लगाने के को दर्शाता है. PrimerPlex (प्रीमियर Biosoft) के रूप में सॉफ्टवेयर के लिए जांच है कि कुश?…
The authors have nothing to disclose.
हम परख विकास और इस पांडुलिपि पर महत्वपूर्ण टिप्पणी के साथ मदद के लिए अल्बर्टो Severini और वैनेसा Goleski धन्यवाद. इस काम कनाडा के जन स्वास्थ्य एजेंसी और औद्योगिक अनुसंधान सहायता कार्यक्रम (कनाडा के राष्ट्रीय अनुसंधान परिषद) द्वारा वित्त पोषित किया गया था. Saskatchewan प्रकाशन फंड के विश्वविद्यालय से अतिरिक्त सहायता प्राप्त हुई थी.
Oligonucleotide name | Company | Sequence1 |
H279BP | Invitrogen, IDT, or other | Biotin-OEFOGAIIIIGCIGGIGAYGGIACIACIAC |
H280 | YKIYKITCICCRAAICCIGGIGCYTT | |
H1612BP | Biotin-OEFOGAIIIIGCIGGYGACGGYACSACSAC | |
H1613 | CGRCGRTCRCCGAAGCCSGGIGCCTT | |
1O, phosphorothioate-C; E, phosphorothioate-G; F, phosphorothioate-A; I, inosine; Y, C or T; R, A or G; K, T or G; S, C or G. |
Table 1. Sequences of the modified oligonucleotides for universal cpn60 PCR.
Name of the reagent | Company | Catalogue number | Comments |
1-Ethyl-3-(3-dimethylamiopropyl) carbodiimide HCl (EDC) | Pierce | 22980 | |
Fluorescent polystyrene beads: MicroPlex Microspheres (Luminex), or Bio-Plex COOH Bead (Bio-Rad) | Luminex or Bio-Rad | Bio-Rad: 171-506xxx where xxx corresponds to the bead identifier | Magnetic beads are becoming available for oligonucleotide coupling and may offer certain advantages. Have not been tried by these authors. |
Capture oligonucleotides (5′ amino C12 modified) | Invitrogen, IDT, or other | various | Desalted purity level is acceptable. Sequences of the capture probes used to characterize vaginal swabs are provided in the manuscript on which this protocol is based13. |
T7 exonuclease | New England Biolabs | M0263S | |
Streptavidin-R-phycoerythrin (SA-PE) | Invitrogen | S-866 | Be careful to obtain high purity SA-PE; this catalog number is recommended |
Thermowell 96 well PCR plates | Fisher | CS006509 | fit into both 96-well thermocycler and BioPlex machine |
Thermowell sealing mat | Fisher | CS006555 | Can be re-used; wash with soapy water, rinse well, and dry |
5M TMAC | Sigma | T3411 | |
Bio-Plex or Luminex instrument | Bio-Rad or Luminex | Bio-Rad : 171-000201 | |
PrimerPlex software for probe design | Premier Biosoft | www.premierbiosoft.com | Suggested for Luminex probe design, although other software platforms may be used |
Table 2. Specific reagents and equipment.
component | μl/assay | μl/100 assays | final concentration |
10x PCR buffer (Invitrogen) | 5 | 500 | 1x |
50 mM MgCl2 (Invitrogen) | 2.5 | 250 | 2.5 mM |
10 mM dNTP | 1 | 100 | 0.2 mM each |
H279BP, 25 μM | 0.25 | 25 | 375 nM |
H1612BP, 25 μM | 0.75 | 75 | 125 nM |
H280, 25 μM | 0.25 | 25 | 375 nM |
H1613, 25 μM | 0.75 | 75 | 125 nM |
Water | 34 | 3400 | — |
Totals | 44.5 | 4450 |
Table 3. Suggested mixtures for PCR with modified cpn60 UT primers (Table 1). The assay is set up for 5 μl of template DNA and 0.5 μl (2.5U) of Taq DNA polymerase (Invitrogen). Normally large volumes are prepared (e.g. sufficient for 100 assays) and stored at -20°C.