Lysing Micro-Organisims with the VK05 15 mL Precellys Lysing Kit

Instrument: Precellys Evolution

Sample: 9 ml of E. coli diluted 1/1000 (3,15x108 CFU/ml)

Protocol:

Precellys® Evolution: 8500 rpm, 3x30 sec, 30 sec break

Culture:

3 dilutions : 1/1 - 1/10 - 1/100
100 µL / plate in duplicate
24 H - 37°C

Lysis in duplicate

Determination of the concentration: % mortality : [(Ci-Cgrinding)/Ci]x100

Results:

After 24h of incubation at 37°C, results were observed. The plate count is linear for E. coli over the range of 30 - 300 CFU on a standard sized Petri dish. We kept the two dilutions in this range to calculate the lysing efficiency

CFU/plate	1/10²	1/10³	Concentration (CFU/mL)	% mortality
1/VK05_15mL	126/130	19/13	1,3 x 10⁴	96%
2/VK05_15mL	156/150	13/19	1,5x10⁴	95%

Table1: results of the lysing step with 9 ml of bacterial suspension, in duplicate. Each lysing suspension was spread on an agar plate in duplicate (100 µl).
Concentration of the starting solution was validated by spreading 100 µl on agar plate of corresponding dilution.

The VK05 15ml kit is very efficient as we observed percentage of mortality > 95% after lysing in comparison with the initial suspension of bacteria

From Bertin Technologies