The
Mini-Extruder
[Mini
Extruder, Parts and Accessories Order Page] [Mini
Extruder Assembly Instructions] [Membrane
Specifications and Drain Disc] [Mini
Extruder Care and Cleaning] [Extrusion
Technique] [Whatman
Liposome Application Brief] [References]
The Avanti Mini-Extruder allows
researchers and scientists to prepare large, unilamellar
vesicles by extrusion in an efficient, rapid manner. The
optional heating block allows the extrusion of unilamellar
vesicles at elevated temperatures, which is critical for the
successful production of vesicles from phospholipids with a
phase transition temperature (Tm) above room
temperature. Constructed of stainless steel and Teflon, this
new design allows rapid cleaning of all wetted parts, which
reduces the "down-time" between production of vesicles from
different lipid species. The Mini-Extruder is available for a
fraction of the cost of a larger extruder. All parts for the
Mini-Extruder are available from Avanti, and the
Mini-Extruder comes with a 30 day workmanship guarantee.
The Avanti Mini-Extruder, Catalog No.
610000, set includes:
Placing the
Stabilizer block-extruder assembly on a hot plate achieves
rapid temperature control for lipids that have transition
temperatures above room temperature.
The particle size distribution of
unilamellar vesicles prepared by extrusion is a function of
the number of passes through the Extruder Membrane. Hydrated
lipid solutions will initially form large, multi-lamellar
vesicles. After the initial pass through a membrane, the
particle size distribution will tend towards a bimodal
distribution. After sufficient passes through the membrane, a
unimodal, normal distribution is obtained. A minimum of eleven
passes through the Extruder membrane is recommended for most
lipids.
The particle size information in Figure 2 was
obtained with a Coulter N4 Plus submicron particle size
analyzer. The particle size analyzer was controlled through a
PC using the N4 Plus software package. The Coulter Particle
Characterization Division may be contacted at (800) 338-8830.
A solution of
1,2-Dioleoyl-sn-Glycero-3-Phosphocholine was made up to 25
mg/ml in DI water. The particle size distribution was measured
for the material before extrusion and for 3 and 11 passes
through a 100nm (0.1micron) membrane. References:
- Subbarao, N.K., R.I. MacDonald, K. Takeshita, and R.C.
MacDonald. (1991). Characteristics of spectrin-induced
leakage of extruded, phosphatidylserine vesicles. Biochim
Biophys Acta 1063:147-54.
- MacDonald, R.C., R.I. MacDonald, B.P. Menco, K.
Takeshita, N.K. Subbarao, and L.R. Hu. (1991). Small-volume
extrusion apparatus for preparation of large, unilamellar
vesicles. Biochim Biophys Acta
1061:297-303.
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