Shane Vontelin van Breda

10 Questions 25 Answers 0 Followers

Questions related from Shane Vontelin van Breda

Can someone provide me with an interpretation of these MBC results against MDR M. tuberculosis?

I determined MBC results for a MDR M. tuberculosis strain and I have some strange results I can't make sense of. The MBC definition I used was a greater than 99 % reduction of viable cells buy...

14 June 2015 5,981 4 View

What could explain the decrease in CFU/ml for my control during a time-kill analysis?

I am working MDR-TB and performing a time-kill assay. I use 1 x 10^5 CFU/ml cells from 7H10 OADC agar (~14 days incubation) and inoculate them into liquid culture (Sauton media). I then monitor...

29 March 2015 8,071 7 View

Could I use stoichiometry ratios to predict MICs for different CFU/ml?

I have determined MIC at > 90 % cellular inhibition using 1 x 10^5 CFU/ml for MTB. I would like to predict how much of my antimicrobial peptide I would require to achieve the same inhibition...

03 September 2014 3,289 3 View

Does anybody have experience with centrifuging low concentrations of bacteria and obtaining a workable pellet?

I have determined MIC's for a certain antimicrobial peptide against M. tuberculosis. My starting CFU/ml is between 1 - 5 x 10^5 cells, using H37Ra. I would like to do various microscopy studies...

09 August 2014 343 6 View

Does anyone have experience with re-autoclaving PBS and simple media?

I work with MTB and usually make up 200ml of 1 x PBS + 0.05 % v/v Tween 80. I also use Sauton media. I was wondering if it would be ok to re-autoclave these items after using them, as I am very...

24 July 2014 4,599 3 View

Can anyone give advice on Fenton reaction inhibition in M. tuberculosis?

I am investigating the mechanism of action of a cationic peptide against MTB. I suspect one of the mechanisms is by the Fenton reaction. One way I would like to prove this is by use of thiourea...

29 June 2014 3,390 6 View

Can anyone suggest methods of M. tuberculosis fixation to slides for microscopy analysis?

I am having problems with my method of fixation. I am attempting to fix my bacteria (M. tuberculosis) to poly - l - lysine slides. My cells are grown in 98 microtiter plates (used for...

27 May 2014 9,644 9 View

What is the difference in Mycobateria growth in flat vs v (conical) - well shaped 96 - well microtiter plates?

I have been determining MICs for M. tuberculosis using 96 - well microtiter plates, flat well shape. After five days, I confirm positive growth by adding alamar blue to my controls. Recently I...

09 March 2014 8,737 1 View

Derivatization of polymyxins using FMOC - Cl?

I am attempting to derivatize polymyxins using FMOC - Cl. I run the derivatives on UPLC, but unfortunately I am struggling to determine which peaks are polymyxins. Briefly, using a vacuum...

08 March 2014 8,553 4 View

Why are my MTB cultures struggling to grow?

I prepare a Mcfarland 1 solution of H37Ra in 1 x PBS containing 0.05 % v/v Tween 80. I add between 1 - 5 ml of the solution to 50 ml 7H9 enriched with OADC and 0.05 % v/v Tween 80. Cells are grown...

04 December 2013 4,318 2 View