The preparation of transforming DNA from Mycoplasma hominis strain Sprott tetr and quantitative studies of the factors affecting the genetic transformation of Mycoplasma salivarium strain S9 tets to tetracycline resistance

1980 ◽  
Vol 26 (9) ◽  
pp. 1147-1152 ◽  
Author(s):  
Anna M. Cerone-McLernon ◽  
Geoffrey Furness

DNA extracted by a standard method from Mycoplasma hominis Sprott, resistant to 100 μg tetracycline, permitted the quantitative genetic transformation of tetracycline-sensitive Mycoplasma salivarium to resistance. The yield was 1 μg DNA/109 cells. This DNA enabled determination of the optimum conditions for making M. salivarium competent with CaCl2 and for studying some factors affecting transformation. Mycoplasma salivarium was transformed to resistance to 10, 20, and 30 μg tetracycline but not to 40 μg. The optimum DNA concentration for transforming resistance to 10, 20, and30 μg tetracycline was the same, i.e., 50 μg DNA/108 viable cells. Treatment with DNase indicated that DNA uptake took 30 min. Competition between transforming DNA and DNA from calf thymus and M. salivarium tets inhibited transformation.


2020 ◽  
Vol 17 (1(Suppl.)) ◽  
pp. 0287
Author(s):  
Ihsan Mahdi Shaheed

            Spectrophotometric method was developed for the determination of copper(II) ion. Synthesized (2,2[O-Tolidine-4,4-bis azo]bis[4,5-diphenyl imidazole]) (MBBAI) was used as chromogenic reagent at pH=5. Various factors affecting complex formation, such as, pH effect, reagent concentration, time effect and temperature effect, have been considered and studied. Under optimum conditions concentration ranged from (5.00-80.00) µg/mL of copper(II) obeyed Beer`s Low. Maximum absorption of the complex was 409nm with molar absorpitivity 0.127x104 L mol-1 cm-1. Limit of detection(LOD) and Limit of quantification were 1.924 and 6.42 μg/mL, respectively. The stoichiometric composition of the chelate is 1:2 (Cu:MBBAI). Experimental results for studying some selected ions as interference were reported. The developed method was successfully applied to determine copper (II) ion in dental filling.  



2021 ◽  
Vol 245 ◽  
pp. 03084
Author(s):  
Wen He ◽  
Chengfeng Dang ◽  
Xing Gao

The calcium content in limestone for chemical industry was determined by atomic absorption spectrometry. The effects of soaking time, soaking reagent and soaking temperature on the determination of calcium content in limestone for chemical industry were discussed by the method of controlling variables, and the optimum conditions for the determination of calcium content in limestone for chemical industry were analyzed. This method has the advantages of easy operation, low interference, high accuracy and sensitivity, and is widely used. The experimental results show that the optimum conditions for the determination of calcium content in limestone for chemical industry are as follows: soaking reagent is 0.6mol/L hydrochloric acid, soaking time is 0.5h, soaking temperature is 70~80 ℃.



2013 ◽  
Vol 32 (1) ◽  
pp. 57 ◽  
Author(s):  
Sandeep Jaggi ◽  
Usha Gupta

A sensitive, simple and selective preconcentration method was developed for the preconcentration of trace amounts of Ni(II) ions using 1-(2-pyridylazo)-2-naphthol (PAN) modified β-cyclodextrin butanediol diglycidyl ether polymer as a solid phase extractant. Potential factors affecting the sorption of Ni(II) were investigated. Meanwhile, the optimum conditions were established. The sorbed Ni(II) was eluted using 5 ml of 2 M HCl. The preconcentrtion factor was 70. The detection limit for Ni(II) was 1.18 ng/ml. The relative standard deviation (RSD %) was >1%. The developed method was successfully applied for the determination of trace Ni(II) in different water and potato chip samples as well as reference alloy samples.



2015 ◽  
Vol 52 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Mir Mahdi Zahedi ◽  
Amir Hosein Amiri ◽  
Mahmoud Nasiri

A simple dispersive liquid–liquid microextraction based on solidification of floating organic droplets coupled with spectrophotometric detection was developed for the determination of nitrite in Chabahar Bay seawater. In the preparation procedure, 2,3-diaminonaphthalene as derivatization reagent reacts with nitrite in acidic medium to form a photometric center of 1-[H]-naphthotriazole (NAT). Product material (NAT) was extracted by dispersive liquid–liquid microextraction with 1-dodecanol as extraction solvent and after centrifugation, the floated droplet was solidified in an ice bath and was easily removed for analysis at λmax = 358 nm. Several important factors affecting the microextraction efficiency were optimized in artificial seawater as a best simulation media. Under the optimum conditions, the absorbance of NAT was linear with nitrite concentrations ranging from 0.1 to 11 μg/mL in seawater. Figures of merit of method such as enrichment factor (52), limit of detection (0.094 μg/mL), and repeatability (N = 6, %RSD = % 5) were evaluated as appropriate. Determination of nitrite in Chabahar coastal zone showed that nitrite concentration varied in the range of 0.77–1.76 μg/mL with an increase of concentration from South to the North of Bay.



2019 ◽  
Vol 12 (48) ◽  
pp. 3-10
Author(s):  
E.K. Abdulaev ◽  
◽  
P.N. Maharathis ◽  
A.I. Kuzhelev ◽  
◽  
...  


Author(s):  
Hind Hadi ◽  
Gufran Salim

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.



Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.



Author(s):  
Т.В. Никитина ◽  
А.А. Кашеварова ◽  
М.М. Гридина ◽  
А.А. Хабарова ◽  
А.Г. Мензоров ◽  
...  

Митотическая нестабильность кольцевых хромосом может приводить к появлению клеточных клонов с различной генетической структурой. В качестве модели нестабильности кольцевых хромосом в митозе мы использовали фибробласты от пациентов с r(8), r(13), r(18) и r(22) и полученные из них индуцированные плюрипотентные стволовые клетки (ИПСК). Линии ИПСК с r(22) имели относительно стабильный кариотип на протяжении десятков (до 60) пассажей и сохраняли неизменную структуру кольцевой хромосомы. Кариотип линий ИПСК с r(8) и r(18) на ранних пассажах стабильный, планируется его изучение на поздних пассажах. Наибольшее разнообразие кариотипа выявлено в линиях ИПСК с r(13), в которых наблюдали различные перестройки и выраженную клеточную гетерогенность. Определение факторов, влияющих на митотическую стабильность кольцевых хромосом, может иметь значение для консультирования пациентов. Mitotic instability of ring chromosomes can lead to the appearance of cell clones with different genetic structure. IPSCs from fibroblasts of patients with r(8), r(13), r(18), and r(22) were used as a model of ring chromosomes mitotic behavior. Karyotypes of iPSC lines with r(8) and r(18) have so far been evaluated only in the early passages, lines with r(22) have maintained a relatively stable karyotype up to 60 passages. The occurrence of rearrangements and cellular heterogeneity was found characteristic for r(13) iPSCs. The determination of factors affecting the ring chromosomes mitotic stability would be beneficial for the patient’s prognosis.



2018 ◽  
Vol 69 (3) ◽  
pp. 627-631 ◽  
Author(s):  
Viorica Ohriac (Popa) ◽  
Diana Cimpoesu ◽  
Adrian Florin Spac ◽  
Paul Nedelea ◽  
Voichita Lazureanu ◽  
...  

Pain is defined as a disagreeable sensory and emotional experience related to a tissue or potential lesion. Paracetamol (Acetaminophen) is the most used non-morphine analgesic. For the determination of paracetamol we developed and validated the high performance liquid chromatography (HPLC) analysis using a Dionex Ultimate 3000 liquid chromatograph equipped with a multidimensional detector. After determining the optimum conditions of analysis (80/20 water / acetonitrile mobile phase, flow rate 1.0 mL / min, detection wavelength 245 nm) we validated the method following the following parameters: linearity of response function, linearity of results, limit (LD = 0.66 mg / mL) and quantification limit (LQ = 2.00 mg / mL), and precision. The method of determining paracetamol by HPLC was applied to 30 samples of serum collected from patients who had pain and were treated with paracetamol.



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