Protein-nucleic acid interaction is an important process in many biological phenomena. In this study, a fluorescence resonance energy transfer (FRET)-based protein-DNA binding assay has been developed, in which a fluorescent amino acid is genetically incorporated into a DNA-binding protein. A coumarin-containing amino acid was incorporated into a DNA-binding protein, and the mutant protein specifically produced a FRET signal upon binding to its cognate DNA labeled with a fluorophore. The protein-DNA binding affinity was then measured under equilibrium conditions. This method is advantageous for studying protein-nucleic acid interactions, because it is performed under equilibrium conditions, technically easy, and applicable to any nucleic acid-binding protein.

Ultraviolet (UV) irradiation is a serious problem for skin health thus the interest in the research to develop sunscreen agent has been increasing. Chalcone is a promising compound to be developed as its chromophore absorbs in the UV region. Therefore, in the present work, we synthesized eight chalcone derivatives through Claisen–Schmidt condensation at room temperature. The evaluation of the optical properties of each chalcone derivatives in the UV region was conducted through spectroscopic and computational studies. The synthesized chalcones were obtained in good yields and they were active in the UV region. The results revealed that more methoxy substituents to chalcone leads toward red shift. All chalcone derivatives have high molar absorptivity value (21,000–56,000) demonstrating that they have the potential to be used as the sunscreen agent. The cytotoxicity assay showed that chalcone derivatives were demonstrating low toxicity toward normal human fibroblast cell, which is remarkable. Therefore, we concluded that the synthesized chalcones in this work were potential to be developed as novel sunscreen agents in real application.

<p class="Default">Chemistry practicum does not have to be complicated and requires expensive apparatus and chemicals, and is considered not environmentally friendly. The concept of small scale chemistry practicum is one of appropriate technology that is packaged elegantly to introduce and embed the principles of green chemistry in every chemistry experiments, and also to enhance the concepts of chemistry through verification and scientific discovery. This study aims to create the newest product, the small scale chemistry practicum module to identify the ability of the students of chemistry education study program, Sanata Dharma University, Yogyakarta in formulating predictions on phenomenon based on the insights they have, making direct observations through small scale chemistry practicum, and explaining the results of observations and emphasis on concepts in detail and depth. This research is the development research with the model of Analysis, Design, Develop, Implement, and Evaluate (ADDIE). Data were analyzed by descriptive analysis and Rasch Model. The results of the study show that the product developed has a perfect and feasible level of readability to be tested. From the content aspect, it presented in perfect criteria, as well as the construction aspect and aspect of language, also shows good value. The students already have quite an excellent ability to predict (average score= 76), observe (average score= 88.5), and explain (average score 87.5). Also, it was noted that students enthusiastically applied POE, and the results of POE students show good person reliability value (0.88) in small scale chemistry experiments. The product developed has been valid, effective, and practical for use in experiments according to experts and teachers, and good student responses (Cronbach's alpha value= 0.92) to the product.</p>

We investigated the cellular uptake efficiencies of differently-sized silica nanoparticles in the presence and the absence of trans-activator of transcription (TAT) peptide. Silica nanoparticles incorporating fluorescent dye molecules with diameters of 30 to 800 nm were synthesized, and the surfaces of the silica nanoparticles were functionalized with TAT peptides or 3-aminopropyltriethoxysilane (APTES). Confocal microscopy and flow cytometry were used to determine the cellular locations and the uptake efficiencies of positively-charged silica nanoparticles (APTES- and TAT-) of various sizes from 30 to 800 nm. The cellular uptake efficiencies of all the differently-sized particles were significantly increased in the presence of TAT peptides. On the basis of an efficient TAT-mediated delivery system, we were able to show that TAT peptides could be used as effective cellular-uptake reagents, particularly for large particles.

Experiment is integral part of chemistry. Through experiments, everyone can verify and or find something new as an alternative solution to attract interest in meaningful chemistry learning. Innovative experimental packaging can be done with Small Scale Chemistry (SSC) to establish the importance of understanding and application related to the use of small amounts of reagents and reduce waste produced during chemistry practicum. This study aims to explore and analyze the science process skills of the second semester students of Chemistry Education Study Program, Sanata Dharma University, which focused for chemistry grade 12 in water electrolysis using straws and mini test tubes as physical chemistry’s experiment and formation reaction of silver mirror uses vial bottle and mirror media as experiment of organic chemistry. The results show that students’ science process skills which includes observation skills with good average score, prediction skills with good enough average score, skills in interpreting data with good average scores, and communication skills with good average score for two kind of experiments conducted. In general, students were enthusiastic in carrying out the two SSC experiments. The students also evaluate the experiments to be able to help develop and improve their soft skills in chemistry learning. Keywords: science process skills, senior high school practicum, small scale chemistry