DEVELOPMENT OF A QUANTITATIVE POLYACRYLAMIDE-GEL ELECTROPHORESIS ANALYSIS USING A MULTICHANNEL RADIOACTIVITY COUNTER FOR THE EVALUATION OF OLIGONUCLEOTIDE-BOUND DRUG CARRIER

A quantitative polyacrylamide gel electrophoresis (PAGE) analysis usin g a multichannel radioactivity counter was designed for the evaluation of P-33-labeled antisense oligonucleotide associated with polymeric d rug carrier (nanoparticles). The proposed analytical method was first validated. The criteria of specificity, linearity, reliability, detect ion and quantification limits, and resolution power were determined. R esults were compared to those obtained using liquid scintillation coun ting of crude samples or after solubilization of gel slices. The propo sed method gave a better linearity and reliability than liquid scintil lation counting of solubilized gel slices. In comparison with the liqu id scintillation counting of crude samples, the method presented the a dvantage of being able to directly separate oligonucleotides differing by only one nucleotide in length. This method was applied for the sep aration of free oligonucleotides and oligonucleotides bound onto nanop articles, allowing quantification of the amount of free and bound olig onucleotides without any further separation steps. Thus, because it is easy and rapid, the quantitative PAGE analysis using a multichannel r adioactivity counter offers interesting possibilities for the characte rization of oligonucleotide nanoparticles. (C) 1996 Academic Press, In c.