Sunday, 21 April 2013


hope you guys will find this interesting
                 Procedures for SDS DNA extraction method
1.     0.15 to 0.2g of fresh plant material was collected in a moter
2.     They were cut with a scissor and grinded into fine pieces by the aid of liquid nitrogen  which was carried out by me accurately well so as prevent the negative effect of liquid nitrogen
3.     Homogeneted mixture of the plant material was then transferred into a 1.5µl eppendorf tube
4.     800µl of SDS buffer was measured and then transferred into the grinded plant material in the eppendorf tube. This is to aid lysing of the lipid membrane
5.     Extra 200µl of the SDS buffer was added and mix well with hand
6.     The eppendorf tube containing the mixture was centrifuge for 5min @12000rpm at a temperature of  4ºC
7.     After which the supernatant was transferred into a new eppendorf tube
8.     200µl of 5M potassium acetate was then added to the supernatant  and this is to separate  the DNA and RNA from other nucleic materials such as protein
9.     Equal volume of phenol-chloroform-Isoamyloalcohol in the ratio of 25:24:1 was now added into the supernatant and then centrifuge also for 12000rpm at a temperature of 4ºC for 10min
10.                        The supernatant was then transferred into a new eppendorf tube without disturbing the interface
11.                        800µl of chilled absolute alcohol or isopropanol was then added into the supernatant and it was kept on ice for 20min. This is to enable the DNA molecule to precipitate since DNA molecule are insoluble in ethanol
12.                        Then it was centrifuge for 10min @ 12000rpm for 4ºC
13.                        The supernatant was now discarded as the DNA and RNA had aggregated  and formed a residue which now settled at the bottom of the eppendorf  tube
14.                        200µl of 70% ethanol was used to wash the DNA pellets. This is to remove salt like potassium
15.                        The  pellets  were left for 30-40min and allow to air dry until the alcohol had completely evaporated
16.                         The pellets were now treated with RNase (an enzymes) which help in digesting the RNA leaving only the DNA
17.                        The pellets were now suspended in 200µl TE (Tris ethylenediaminetetraacetic acid). The presents of the Tris is to keep the pH of the DNA constant and the EDTA serve as a chelating agent therefore chelate ions and some enzymes from degrading the DNA.
18.                        The suspended pellet was then stored at -20ºC  

Friday, 8 February 2013


polymeric micelle is a nanoparticle structure by one hydropholic shell and one hydrophobic core. it can be divide into two category :hydrophobically assembled micelles and polygon-complex micelles.
the formal one usually consist ofanphiphilic copolymers with a hydrophpbic block and a hydrophilic block balance between those two block in an aqueous medium induces spontaneous formation of nano-sized particulate.
Abstract: In past two decades poly lactic-co-glycolic acid (PLGA) has been among the
most attractive polymeric candidates used to fabricate devices for drug delivery and tissue
engineering applications. PLGA is biocompatible and biodegradable, exhibits a wide range
of erosion times, has tunable mechanical properties and most importantly, is a FDA approved
polymer. In particular, PLGA has been extensively studied for the development of devices for
controlled delivery of small molecule drugs, proteins and other macromolecules in
commercial use and in research. This manuscript describes the various fabrication techniques
for these devices and the factors affecting their degradation and drug release.
Keywords: poly lactic-co-glycolic acid; drug delivery; PLGA degradation; sustained release;
PLGA fabrication techniques.