All DLS Sizing
August 9, 2016
Present: Amir, Ina, Mina
Task: Size and detect charge of the DSPC:Cholesterol:DSPE-PEG2000-MALEIMIDE liposomes received from Avanti Polar Lipids using a Malvern DLS
Materials: DSPC:Cholesterol:DSPE-PEG2000-MALEIMIDE liposomes, Malvern DLS
- 5mL of 30 mg/mL of liposomes were aliquoted into 11 aliquots of 450 µL each in the biosafety cabinet, with the lights shut off.
DLS sample preparation
- 500 µL of 1xPBS was placed in a new, clean cuvette
- 1 µL of the liposomes was transferred into the cuvette (1:500 dilution) and mixed by tapping the cuvette
- Bubbles were removed by tapping the cuvette and the outside of the cuvette was cleaned with a kim wipe before inserting into the Malvern DLS.
- Count rate > 200 is good; 250 is optimal
- Attenuator- 6-7 is good; anything much smaller or higher is not ideal
- Link to DLS exported data
August 10, 2016
Present: Amir, Mina
In this run, another vial of liposomes was used, it is marked sizing, the reason why a different one is used is because first run’s sample was taken out of the last vial.
For this run, a 1:500 dilution was used.
Alynylam was used for measurements.
Two peaks were seen in intensity measurements, one at ~150, another at 5 microns, lower deviation was seen, average for measurement 1 was 130, for 2 and 3 were 210.
Diluted 2µL of liposomes (mixed by tapping the tube), in 100µL of homemade PBS. Used L-nylam according to expert advice.