How do I prepare dead cell controls for LIVE/DEAD cell viability assays?
There are two easy options. One is to heat-inactivate the cells by placing at 60 degrees C for 20 minutes. The second is to subject the cells to 70% ethanol. Alcohol-fixed cells can be stored indefinitely in the freezer until use, potentially up to several years.
Centrifuge cells, pellet, and remove supernatant.
Fix cells: Add 10 mL ice cold 70% ETOH to a 15 mL tube containing the cell pellet, adding dropwise at first while vortexing, mix well.
Store in freezer until use.
When ready to use, wash twice and resuspend in buffer of choice.
Biofilm formations in nasopharyngeal tissues of patients with nasopharyngeal osteoradionecrosis.
Authors:Tsai YJ, Lin YC, Wu WB, Chiu PH, Lin BJ, Hao SP,
Journal:Otolaryngol Head Neck Surg
PubMed ID:23348872
'Objective Determine the presence of nasopharynx biofilms in patients with nasopharyngeal cancer (NPC) and osteoradionecrosis (ORN) and patients with NPC but no ORN. Study Design Cross-sectional study. Setting Tertiary referral medical center. Subjects and Methods We enrolled 27 patients with NPC from our outpatient clinic during January 2010 to June ... More
Comparison of methods for evaluation of the bactericidal activity of copper-sputtered surfaces against methicillin-resistant Staphylococcus aureus.
Authors:Rio L, Kusiak-Nejman E, Kiwi J, Bétrisey B, Pulgarin C, Trampuz A, Bizzini A,
Journal:Appl Environ Microbiol
PubMed ID:22983970
Bacteria can survive on hospital textiles and surfaces, from which they can be disseminated, representing a source of health care-associated infections (HCAIs). Surfaces containing copper (Cu), which is known for its bactericidal properties, could be an efficient way to lower the burden of potential pathogens. The antimicrobial activity of Cu-sputtered ... More
Fratricide is essential for efficient gene transfer between pneumococci in biofilms.
Authors:Wei H, Håvarstein LS,
Journal:Appl Environ Microbiol
PubMed ID:22706053
Streptococcus pneumoniae and a number of commensal streptococcal species are competent for natural genetic transformation. The natural habitat of these bacteria is multispecies biofilms in the human oral cavity and nasopharynx. Studies investigating lateral transfer of virulence and antibiotic resistance determinants among streptococci have shown that interspecies as well as ... More
Comparison of different live/dead stainings for detection and quantification of adherent microorganisms in the initial oral biofilm.
Authors:Tawakoli PN, Al-Ahmad A, Hoth-Hannig W, Hannig M, Hannig C,
Journal:Clin Oral Investig
PubMed ID:22821430
The aim of the present study was to investigate different fluorescence-based, two-color viability assays for visualization and quantification of initial bacterial adherence and to establish reliable alternatives to the ethidium bromide staining procedure. Bacterial colonization was attained in situ on bovine enamel slabs (n?=?6 subjects). Five different live/dead assays were ... More
Rapid Bacterial Detection during Endodontic Treatment.