Uv 1700 pharmaspec uv vis spectrophotometer

All chemicals, reagents, microbial growth media and protein purification resins were purchased from commercial sources and at highest available quality. Oligonucleotides (Table S1 in the Supplementary Information) were supplied by Thermo Fisher Scientific and the pETDuet-1 vector was supplied by Novagen. Endonucleases were supplied by Thermo Scientific. GeneJET Gel Extraction Kits and GeneJET Plasmid Miniprep Kits from Thermo Scientific were used extraction of fragment and plasmid DNA. Chelating Sepharose Fast Flow gel supplied form GE Healthcare was used for the immobilized metal ion affinity chromatography (IMAC). Either a NanoDrop® ND-1000 Spectrophotometer or a UV-1700PharmaSpec UV–VIS spectrophotometer from Shimadzu was used for spectrophotometric measurements.

The percentage (%) drug encapsulation-efficiency (EE) of the CHX-loaded/Ca(OH)₂ microparticles (at formulations of CHX:Ca(OH)₂/25 mg and CHX:Ca(OH)₂/50 mg) was determined by indirect-assay method. Microparticles were washed with distilled water, centrifuged and the supernatant was collected. Based on the standard curve plotted earlier, the amount of non-encapsulated (free) CHX in the supernatant was measured spectrophotometrically at 289 nm (UV-1700 Pharma Spec UV-VIS Spectrophotometer, Shimadzu, Japan) (n = 7). From the above estimated value, the amount of encapsulated CHX was determined. The percentage (%) of drug encapsulation-efficiency (EE) and drug-loading (DL) were calculated using Equations (1) and (2).

The TMZ and O6BG EE values of the prepared PLGA NPs were assessed by UV–Vis spectrophotometry, using the following Equation (2): $EE= \frac{total amount of drug- amount of free drug}{total amount of drug} \times 100$
Non-encapsulated TMZ and O6BG molecules were separated from the NPs colloidal suspension by centrifugation (30 min, 14100× g, MiniSpin^®plus, Eppendorf, Germany) and quantified (UV-1700 PharmaSpec UV-Vis spectrophotometer, Shimadzu, Kyoto, Japan) at 240 nm and 329 nm for O6BG and TMZ, respectively. The results were correlated to control samples corresponding to total amount of drug. For the optimized formulation, three independent experiments were conducted, and obtained results are expressed as the mean and SD. Statistical analysis was performed using the t-student test.

The Chl concentration (Chl a, Chl b, and Chl a + b) and composition (Chl a/b) of all 475 species were analysed, with three replications for each species. Fresh leaves (0.1 g) were weighed and extracted using 95% ethanol for three times, and the extraction solutions were combined, filtered and adjusted to a constant volume of 50 mL. Measurements were conducted using a spectrophotometer (UV-1700pharmaSpec UV–Vis spectrophotometer, Shimadzu Corporation, Kyoto, Japan). According to the Lambert–Beer law, the relationships between the Chl solution and optical density are. $${\text{D}}_{665}=83.31{\text{C}}_{\text{a}}+18\text{.60}{\text{C}}_{\text{b}}$$ $${\text{D}}_{649}=24.{\text{54 C}}_{\text{a}}+44.{\text{24 C}}_{\text{b}}$$ $$\text{G}={\text{C}}_{\text{a}}+{\text{C}}_{\text{b}}$$
where D₆₆₅ and D₆₄₉ are the optical densities of the Chl solution at wavelengths of 665 and 649 nm, respectively. C_a and C_b are the concentrations of Chl a and Chl b (g L⁻¹), respectively. The coefficients 83.31 and 18.60 are the specific absorptions of Chl a and Chl b at a wavelength of 665 nm, while 24.54 and 44.24 are the specific absorption values at a wavelength of 649 nm. The concentrations of Chl a, Chl b, and total Chl (mg g⁻¹ fresh mass), along with Chl composition, can consequently be calculated as^{14 (link),15 (link)}: $$\text{Chl}a\left({\text{mg g}}^{-1}\right)={\text{C}}_{\text{a}}\times 50/\left(1000\times 0.1\right)$$ $$\text{Chl}b\left({\text{mg g}}^{-1}\right)={\text{C}}_{\text{b}}\times 50/\left(1000\times 0.1\right)$$ $$\text{Total}\text{Chl}\text{concentration}=\text{Chl}a+\text{Chl}b$$ $$\text{Chl}\text{composition}=\text{Chl}a/\text{Chl}b$$

At 3000 rpm blood was centrifuged for 10 min to separate serum. In the serum, the activity level of SGOT and SGPT was analyzed by kinetic method using the commercial kit (Robonik India Pvt. Ltd, Navi Mumbai). Absorbance was measured using a Shimadzu UV-1700 pharma spec UV–VIS spectrophotometer. Due to the oxidation of NADH to NAD, there was a significant decrease in absorbance measured at 340 nm, which is directly proportional to the activity of SGOT and SGPT in the sample. Its activity is expressed in Units/L.