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Susan E Sefers

Publications and source records attributed to Susan E Sefers.

6 recordsLinked to original sources

Simultaneous amplification and identification of 25 human papillomavirus types with Templex technology.

The majority of existing human papillomavirus (HPV) genotyping assays are based on multiplex PCR using consensus or degenerate primers. We developed a Templex HPV assay that simultaneously detects and identifies 25 common HPV genotypes in a single-tube reaction using type-specific primers for the HPV-specific E6 and E7 genes. The analytical sensitivities of the Templex assay for HPV type 16 (HPV-16), -18, and -56 were 20, 100, and 20 copies per reaction mixture, respectively. The Templex assay provides semiquantitative information on each type when multiple HPV types coexist in one reaction. We tested 109 clinical cervical specimens previously evaluated with the Digene HC2 high-risk HPV DNA test and found 95.4% concordance between the assay results. The Templex assay provided type-specific results and found multiple types in 29.2% (14 of 48) of high-risk HPV-positive samples. The entire Templex procedure, including DNA extraction, can be completed within 5 hours, providing a rapid and reliable diagnostic tool for HPV detection and typing that is amenable to automation.

Cervix Uteri↗

QIAamp MinElute virus kit effectively extracts viral nucleic acids from cerebrospinal fluids and nasopharyngeal swabs.

BACKGROUND: Nucleic acid preparation from a variety of clinical specimens requires efficient target recovery and amplification inhibitor removal and is critical for successful molecular diagnosis. The QIAamp MinElute Virus kit (Qiagen Inc., Valencia, CA) was compared to the two existing methods currently used in our laboratory, IsoQuick (Orca Research Inc., Bothell, WA) for DNA extraction and RNAzol B (Leedo Laboratories Inc., Houston, TX) for RNA extraction, of viral nucleic acids. STUDY DESIGN: A total of 150 clinical specimens, including cerebrospinal fluid (CSF) and nasopharyngeal swabs (NPS), were used to determine the extraction efficiency of the MinElute compared to the other two methods. Nucleic acid recovery, hands-on time, turn-around-time and cost were compared across all kits. RESULTS: There was complete concordance between the MinElute and IsoQuick/RNAzol kits when herpes simplex virus (HSV), Epstein-Barr virus (EBV), varicella-zoster virus (VZV), influenza A virus or enteroviruses were detected using a colorimetric microtiter plate PCR system. The kits were equivalent in their ability to detect either DNA or RNA with superior ability to recover a high quality and quantity of RNA. With the potential to process larger specimen volumes, the MinElute kit can significantly shorten processing time from 2h to 50-55min. CONCLUSIONS: Although relatively high test kit costs were noted, the MinElute kit provides another rapid and user-friendly specimen processing tool in the diagnostic molecular microbiology laboratory.

Cerebrospinal Fluid↗

Comparative evaluation of three commercial systems for nucleic acid extraction from urine specimens.

A nucleic acid extraction system that can handle small numbers of specimens with a short test turnaround time and short hands-on time is desirable for emergent testing. We performed a comparative validation on three systems: the MagNA Pure compact system (Compact), the NucliSens miniMAG extraction instrument (miniMAG), and the BioRobot EZ1 system (EZ1). A total of 75 urine specimens submitted for polyomavirus BK virus detection were used. The human beta-actin gene was detected on 75 (100%), 75 (100%), and 72 (96%) nucleic acid extracts prepared by the miniMAG, EZ1, and Compact, respectively. The miniMAG produced the highest quantity of nucleic acids and the best precision among the three systems. The agreement rate was 100% for BKV detection on nucleic acid extracts prepared by the three extraction systems. When a full panel of specimens was run, the hands-on time and test turnaround time were 105.7 and 121.1 min for miniMAG, 6.1 and 22.6 min for EZ1, and 7.4 and 33.7 min for Compact, respectively. The EZ1 and Compact systems processed automatic nucleic acid extraction properly, providing a good solution to the need for sporadic but emergent specimen detection. The miniMAG yielded the highest quantity of nucleic acids, suggesting that this system would be the best for specimens containing a low number of microorganisms of interest.

Actins↗