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Bronchial Aspirates in the Diagnosis of Pulmonary Tuberculosis: Bronchial Aspirates by CA

Specimens were regarded as positive for AFB even if only one or two cells per 300 fields were observed. Cultures were grown using egg-based Ogawa medium, and growth was observed for 8 weeks, after which the M tuberculosis complex was identified using the Accuprobe test (Gen-Probe; San Diego, CA). All bronchial aspirates were stored at — 70°C until 400 broncho-scopic procedures were completed, and then the CA tests were performed collectively.
Detection of the M tuberculosis Complex in Bronchial Aspirates by CA
The CA test was performed according to the instructions of the manufacturer. CA uses the polymerase chain reaction (PCR) nucleic acid amplification technique, nucleic acid hybridization, and colorimetric detection of M tuberculosis. With the benchtop CA analyzer (Roche Diagnostics Systems), the amplification, addition of denaturation agent, and detection of the amplified product were automated. Briefly, the procedures are as follows. Canadian family pharmacy Click Here NaOH/NALC-treated specimens were washed with a respiratory specimen wash solution, after which organisms were lysed by inoculation with a respiratory specimen lysis reagent. Finally, specimens were made ready for amplification by the addition of a respiratory specimen neutralization reagent. After the processed specimens were added to the amplification mixture, which contains an internal control and urasyl-N-glycosylase, PCR was performed. The internal control identifies specimens containing substances that may interfere with PCR amplification. When heated in the first thermal cycling step at the alkaline pH of the amplification mixture, urasyl-N-glycosylase breaks the carry-over amplicon DNA at deoxyuridine, thereby rendering the DNA nonamplifiable. The required number of cycles is automatically performed by the CA. Following PCR amplification, a suspension of magnetic particles coated with an oligonucleotide probe specific for M tuberculosis is added to the amplicon.