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.
|
