Löwenstein-Jensen (L-J) L-J with RNA L-J with pyruvic acid Middlebrook 7H10
If growth occurs, confirm by AFB smear
Confirm by AFB smear
Reinocúlate solid media
^Mycobacterium Growth Indicator Tube.
Figure 45-1 A flowchart for specimen processing for isolation of mycobacteria.
Digestion-decontamination procedures should be as gentle as possible, with no more than an overall contamination rate of 5%.5
Overview. Commonly used digestion^eœntamina-tion methods are the sodium hydroxide (NaOH) method the Zephiran-trisodium phosphate method, and the JV-acetyl-l-cysteine (NALC)-NaOH method. The NALC-NaOH method is detailed in Procedure 45-1. Of note, another decontaminating procedure using oxalic acid is very useful for treating specimens known to harbor gram-negative rods, particularly Pseudomonas and Proteus, which are extremely troublesome conta minants. NaOH is a commonly used decontaminant th< is also mucolytic. Several agents can be used to liquefy^ clinical specimen, including NALC, dithiothreitol (spl tolysin), and enzymes. None of these agents are inbH bitory to bacterial cells. In most procedures, liquefacd^j (release of the organisms from mucin or cells) is enhanced by vigorous mixing with a vortex type of mixei, in a closed container. Following mixing, the contain^ should be allowed to stand for 15 minutes before ope#jj ing, to prevent the dispersion of fine aerosols generate during mixing. Of utmost importance during process™ is strict adherence to processing and laboratory safera protocols. All of these procedures should be carried
1v-Acetvl-l-Cysteine-Sodium Hydroxide Method for Liquefaction and Decontamination of Specimens
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