Judul: Telaah pengklonan gen protease dari Bacillus stearo thermophilus ke dalam Escherichia coli
Abstrak: Fragmen-fragmen genom dari Bacillus stearothermophilus, yang dipotong secara parsial dengan Eco RI atau HindIII, telah diklon dalam Escherichia coli dengan teknik shot gun cloning menggunakan plasmid pRK415 sebagai vektornya untuk gen protease. Media agar MacConkey (Jennings dan Beacham, 1989) dengan sedikit modifikasi dipakai untuk deteksi koloni pembawa plasmid rekombinan atau plasmid nonrekombinan. Media tersebut terdiri dari 10 g tripton, 5 g ekstrak kha­ mir, 10 g laktose, 0.075 g neutral red, 15 g agar dalam 1 L dH20, pH diatur pada 7 .4. Untuk deteksi ekspresi gen protease, media tersebut ditambahkan 2 % susu skim. Media ini dinamakan SMMCA (skim milk modified MacConkey agar). Penghilangan kristal violet, garam empedu dan garam memberikan hasil yang baik untuk deteksi koloni-koloni tersebut. Sel koinpeten untuk keperluan pengklonan disiapkan dengan metode miniprep, sesuai prosedur Lederberg dan Cohen (1974) dengan sedikit modifikasi, dilakukan dengan cara mensentrifusi 1.5 mL kultur fase log dalam tabung mikro setelah sebe­lumnya diinkubasikan selama 30 menit pada 0°C. Pelet sel dicuci dengan 1 mL 0.1 M CaC12 dingin, kemudian sel disuspensikan dalam 0.5 mL 0.1 M CaC12 dingin dan diinkubasikan pada 0°C selama 20 menit, sentrifusi terakhir dilakukan dan pelet sel disuspensikan dalam 0.2 mL 0.1 M CaC12 dingin, pada kondisi ini sel siap digu­ nakan untuk transformasi. Isolasi DNA kromosom dengan metode Marmur (1961) mendapatkan DNA dengan kualitas yang cukup baik, dan dapat dipakai untuk keperluan kloning, walauiv pun dilakukan tidak sampai pada tahap pemurnian lanjutan seperti penghilangan RNA dan pemekatan. Dari 500 mL kultur fase log diperoleh lebih kurang 2 mg DNA kromosom. ...
Keyword: Escherichiacoli, Proteinase

Judul: Transfer DNA Bacillus licheniformis ke dalam sel Escherichia coli dengan menggunakan MgCl2 dan PEG - 6000
Abstrak: Penelitian ini mencoba mentransformasikan sifat genetik yang ada pada Bacillus licheniformis ke dalam sel Escherichia coli dengan perlakuan MgCl2 dan PEG-6000. Sifat genetik utama yang diharapkan tertransformasi adalah enzim protease pada B. licheniformis ke dalam sel E. coli yang semula tidak memiliki sifat proteolitik. Proses transformasi dimulai dengan mengisolasi DNA B. licheniformis dengan menggunakan sodium dodesil sulfat 25 persen untuk memecah dinding dan membran sel. Agar dinding sel lebih mudah pecah, sebelum penambahan sodium dodesil sulfat 25 persen dilakukan sonikasi pada frekuensi 100 kHz selama 8 10 menit. DNA diekstrak dari campuran komponen- komponen sel lainnya dengan menggunakan pelarut-pelarut organik, yaitu sodium perklorat 5M dan kloroform-isoanil alkohol (24: 1) serta sentrifusi, selanjutnya DNA digumpal- kan dengan campuran etanol 70 persen NaCl 5M (10:1). Pembentukan protoplas E. coli dilakukan dengan menggunakan enzim lisosim 10 mg/ml bufer TEN untuk memecah dinding sel dan protoplas yang diperoleh disuspensikan dalam larutan sukrosa 1M MgCl2 0.04M (1:1) untuk mencegah lisis karena tekanan osmosis. Transformasi dilakukan pada suhu kamar ...
Keyword: Transfer DNA, Bacillus licheniformis, Escherichia coli, MgCl2, PEG 6000, Struktur dan sifat umum DNA, Replikasi DNA, Isolasi DNA dari bakteri

Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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