Specimen Preparation

Cards (11)

  • Back-up broth medium

    Supplemental or enrichment broth
  • Back-up broth medium
    • Fluid medium
    • For small numbers of organisms present
    • For anaerobes in aerobic cultures
    • For organisms that may be damaged by previous or concurrent antimicrobial therapy
  • Back-up broth medium use
    1. Incubated for a certain period
    2. Then subcultured
  • Common back-up broths
    • Thioglycollate (thio) broth
    • Brain-heart infusion broth (BHIB)
    • Tryptic soy broth (TSB)
    • Lim broth (used to enhance the group of beta streptococci)
  • Lim broth
    Used to enhance the group of beta streptococci
  • Specimen types
    • Swab
    • Tissue
    • Fluid
  • Tissue specimen preparation
    1. Homogenization (grinding)
    2. Minced with sterile scissors and forceps into small pieces
  • Fluid specimen preparation
    1. Concentration of large volumes of fluids (to increase the recovery of bacteria)
    2. Centrifugation (for fluid greater than 1 ml, inoculate media and prepare smears)
    3. Filtration (for thin fluid consistency to avoid filter clogging)
  • Sterile body fluids
    • Peritoneal fluids
    • Pleural fluids
    • Continuous ambulatory peritoneal dialysis fluid [CAPD]
  • Specimen decontamination
    For legionellae or mycobacteria
  • Swab specimen preparation
    1. 1st swab inoculated to culture media and make a direct smear
    2. 2nd swab placed into 0.5 to 1.0ml of broth or saline and then vortexed to loosen material from the swab to produce an even suspension of organisms