Addition Of Bovine Serum Albumin Research Articles

Synthesis and Characterizations of MoS2 Nanoflowers and Spectroscopic Study of their Interaction with Bovine Serum Albumin.

Molybdenum disulfide nanoflowers (MoS2 NFs) were prepared by hydrothermal method. The prepared MoS2 NFs was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), specific surface areas, Raman and X-ray photoelectron spectroscopy (XPS). The characterization results show that the flower-like spherical MoS2 is composed of many ultra-thin nanosheets with an average diameter of about 300-400 nm. MoS2 NFs also exhibits excellent UV-vis absorption and high fluorescence intensity. In order to explore the biological behavior of MoS2 NFs, the interaction between MoS2 NFs and bovine serum albumin (BSA) was studied by UV-Vis absorption, fluorescence, synchronous fluorescence spectra, and cyclic voltammetry. The results of absorption and fluorescence show that MoS2 NFs and BSA interact strongly through the formation of complexes in the ground state, and the static quenching is the main mechanism. The Stern-Volmer constant and the quenching constant was calculated about 3.79×107 L mol-1 and 3.79×1015 L mol-1 s-1, respectively. The synchronous fluorescence implied that MoS2 in the complex may mainly bind to tryptophan residues of BSA. The cyclic voltammograms indicated that the addition of BSA makes electron reduction of MoS2 NFs more difficult than the corresponding free state. The results show that hydrophobic forces play a major role in the binding interaction between BSA and MoS2 NFs.

Exploring albumin-sulfonephthalein dyes interactions by a chemometric-assisted and multi-technique equilibria analysis in solution

Albumin is undoubtedly the most studied protein thanks to its widespread diffusion and biochemistry; despite its binding ability towards different dyes, provoking dye’s colour change, has been exploited for decades for quantification purposes, the joint effect of working pH, ionic strength, and dye’s pKa still remains only sporadically discussed. In the present study, the interaction of Bovine Serum Albumin (BSA) with five dyes belonging to the sulfonephthalein group, Bromophenol Blue (BPB, pKa = 3.75), Bromocresol Green (BCG, pKa = 4.42), Chlorophenol Red (CPR, pKa = 5.74), Bromocresol Purple (BCP, pKa = 6.05) and Bromothymol Blue (BTB, pKa = 6.72), is investigated at four working pH values (3.5, 6.0, 7.5 and 9.0) and two ionic strength conditions by UV–Vis spectroscopy. Principal Component Analysis is then applied to rationalize dye behavior upon BSA addition at each pH value and to summarize the protein effect on dyes’ spectral features, identifying three general behaviors. The most relevant systems are then submitted to further characterization involving a solution equilibria study aimed at determining conditional binding constants for the selected DSA-dye adducts and fluorescence, CD, and 1H NMR spectroscopy to evaluate the binding effect on the species involved.

Oxidative Stripping of Starch-AgNPs for Nanomolar Indirect Electrochemical Sensing of BSA Using an L-Cysteine Modified Glassy Carbon Electrode

In this study, an L-cystine-modified glassy carbon electrode (GCE) was developed as an electrochemical platform based on AgNP oxidative stripping for nanomolar indirect detection of bovine serum albumin (BSA) biomacromolecules. The Poly-L-Cys was formed by L-cysteine (L-Cys) monomers electro-polymerization on the GCE surface. L-Cys pending groups interacted with AgNPs through Ag-S chemical bonds while it interacted with BSA through van der Waals forces and hydrogen bonding. To characterize the bare GCE and GCE/L-Cys, cyclic voltammetry and electrochemical impedance spectroscopy were used. The oxidative stripping of AgNPs by the addition of BSA was monitored using linear sweep stripping analysis.

Turn-On Fluorescent Probe for BSA Detection Constructed by Supramolecular Assembly.

The fluorescent probe method has attracted significant research attention due to its high sensitivity and reproducibility in detecting bovine serum albumin (BSA). In this study, we constructed a fluorescent probe for BSA detection by assembling an amphiphilic organic fluorescent molecule, termed 2-(2'-hydroxyphenyl) benzothiazole (HBT-11), with BSA. In an aqueous solution, HBT-11 exhibited a weak fluorescence emission at 501 nm. However, the addition of BSA substantially enhanced the fluorescence emission at 501 nm, indicating that the assembly was driven by electrostatic interactions between HBT-11 and BSA. HBT-11, serving as a fluorescent probe for BSA detection, demonstrated a limit of detection (LOD) as low as 3.92 nmol L-1, excellent photostability, high selectivity, and robust anti-interference capability. Notably, we successfully applied HBT-11 for detecting BSA in fetal bovine serum and selectively imaging BSA in HeLa cells.

Electrochemical Sensing with Spatially Patterned Pt Octahedra Electrodes

AbstractLocally controlling the position of electrodes in 3D can open new avenues to collect electrochemical signals in complex sensing environments. Implementing such electrodes via an electrical network requires advanced fabrication approaches. This work uses corner lithography and Pt ALD to produce electrochemical 3D electrodes. The approach allows the fabrication of (sub)micrometer size Pt octahedra electrodes spatially supported over 3D fractal‐like structures. As a proof of concept, electrochemical sensing of ferrocyanide in biofouling environments, e.g., bovine serum albumin (BSA) and Pseudomonas aeruginosa (P. aeruginosa), is assessed. Differences between before and after BSA addition show a reduction in the active electrode surface area (ΔAeff) ≈49% ± 7% for the flat electrode. In comparison, a ΔAeff reduction of 25% ± 2% for the 3D electrode has been found. The results are accompanied by a 24% ± 16% decrease in peak current for the flat Pt substrate and a 14% ± 5% decrease in peak current for the 3D electrode 24 h after adding BSA. In the case of P. aeruginosa, the 3D electrode retains electrochemical signals, while the flat electrode does not. The results demonstrate that the 3D Pt electrodes are more stable than their flat counterparts under biofouling conditions.

Interaction mechanism of a pesticide, Azoxystrobin with bovine serum albumin: Assessments through fluorescence, UV–Vis absorption, electrochemical and molecular docking simulation techniques

The current study's objective was to investigate how an antifungal pesticide Azoxystrobin (AZO) interacts with bovine serum albumin (BSA) under conditions that simulate a physiological medium (pH 7.4). This investigation was carried out using various experimental (UV–Vis absorption, steady-state fluorescence and 3-D fluorescence spectroscopies, and electrochemical) and theoretical (molecular docking and molecular dynamics simulations) methods. The fluorescence quenching data demonstrated that AZO caused fluorescence quenching in BSA, and this quenching process was attributed to the static quenching mechanism. By examining the fluorescence quenching of BSA at three different temperatures, it was determined that the binding constants for the AZO-BSA complexes were approximately 104 M−1 in magnitude, while the same magnitude of the binding constant was found by the electrochemical method. This indicates that the interaction between AZO and BSA was of moderate strength. This was further validated by the changes observed in the UV–Vis spectrum of BSA following the addition of AZO. The thermodynamic information, including ΔH and ΔS, revealed that the interaction forces primarily involved van der Waals forces as well as hydrogen bonds. The negative Gibbs free energy indicated that the reaction is spontaneous. In the theoretical investigation, the comparison highlights a remarkable consistency in how AZO interacts with the BSA active site over various time points. Hydrogen bonding and hydrophobic interactions consistently play a role in ensuring the stable and specific binding of the ligand. Moreover, the 3-D fluorescence spectral findings revealed alterations in the surrounding microenvironment of protein fluorophores when AZO binds. Upon analyzing the electrochemical data, it was observed that there was a consistent decrease in the peak currents of AZO when BSA was added to solutions containing AZO. The primary cause of this decrease in the peak currents was the reduction in the equilibrium concentration of AZO due to the addition of BSA. Furthermore, the formation of a non-electroactive complex between BSA and AZO, which impedes electron transport between AZO and the working electrode, accounts for these decreases. As a result, it can be said that the understanding of how AZO binds to BSA offers valuable insights that can be applied in the food, human health, and environment sectors.

Optimizing environmental viral surveillance: bovine serum albumin increases RT-qPCR sensitivity for high pathogenicity avian influenza H5Nx virus detection from dust samples

ABSTRACT The latest outbreaks of high pathogenicity avian influenza viruses (HPAIVs) were the most widespread ever seen in Europe, entailing considerable economic costs and raising public health concerns. Virological surveillance protocols involve reverse transcription quantitative polymerase chain reactions (RT-qPCR) from tracheal and cloacal swabs, which are laborious to perform on a large scale and require special skills. Environmental sampling, and especially dust collection, may represent a relevant alternative, as it is cheap, non-invasive for animals, simpler, and quicker to carry out. The main drawback of dust samples is that they may contain high amounts of organic substances that can inhibit RT-qPCR reactions. Bovine serum albumin (BSA) is a molecule known to facilitate DNA polymerization in the presence of numerous inhibitors, including those from feces, litter, or food. We tested its use on dust samples collected on 107 farms localized in areas affected by epizootics of clade 2.3.4.4b HPAIV H5N1. We used a latent class modeling approach to compare the performance of three detection protocols: (i) BSA addition to the RT-qPCR reaction mix, (ii) dilution of template RNA, and (iii) a control protocol. Our results indicate that BSA addition to the RT-qPCR reaction mix improved the sensitivity of the method, by neutralizing inhibitors’ effect. Indeed, for hemagglutinin (HA) or matrix (M) RNA detection, the sensitivity of the BSA protocol was the highest, followed by that of the control protocol, and that of the dilution protocol. Our results suggest that the use of BSA could be routinely implemented in HPAIV dust monitoring RT-qPCR protocols. IMPORTANCE With the circulation of high pathogenicity avian influenza viruses having intensified considerably in recent years, the European Union is considering the vaccination of farmed birds. A prerequisite for this vaccination is the implementation of drastic surveillance protocols. Environmental sampling is a relevant alternative to animal sampling. However, environmental samples often contain inhibitory compounds in large enough quantities to inhibit RT-qPCR reactions. As bovine serum albumin is a molecule used in many fields to overcome this inhibitory effect, we tested its use on dust samples from poultry farms in areas heavily affected by HPAIV epizootics. Our results show that its use significantly increases the sensitivity of the method.

Detection of acid protease using the fluorescent probe 3,3′-dipentylthiacarbocyanine iodide-BSA

In this work, an ‘on-off’ fluorescent probe was developed for detection of acid protease (ACP) based on bovine serum albumin (BSA) as the substrate. 3,3′-Dipentylthiacarbocyanine iodide, DiSC5(3), exhibits very weak fluorescence emission in aqueous solution, but following the addition of BSA, due to hydrophobic interactions between them, DiSC5(3) forms an aggregate with BSA and emits strong red fluorescence. When ACP is added, the fluorescence emission of the DiSC5(3)-BSA system is quenched because BSA is hydrolysed into peptide fragments and amino acids by ACP, destroying the DiSC5(3)-BSA system. The degree of fluorescence quenching of the DiSC5(3)-BSA system is proportional to the concentration of ACP over a range of 10–40 μg/mL, with a linear equation y = −4.8270x + 509.7066, a correlation coefficient R2 = 0.9986, and a detection limit of 1.44 μg/mL. The method has advantages including simple operation, high sensitivity and good selectivity, and can be used for detection of ACP in real samples.

Role of Bovine Serum Albumin Addition in Micellization and Gel Formation of Poloxamer 407.

The combination of the thermoresponsive polymer and protein has demonstrated great promise in its applications in drug delivery and tissue engineering fields. This study described the impact of bovine serum albumin (BSA) on the micellization and sol-gel transition behaviors of poloxamer 407 (PX). The micellization of aqueous PX solutions with and without BSA was examined using isothermal titration calorimetry. In the calorimetric titration curves, the pre-micellar region, the transition concentration region, and the post-micellar region were observed. The presence of BSA had no noticeable impact on critical micellization concentration, but the inclusion of BSA caused the pre-micellar region to expand. In addition to studying the self-organization of PX at a particular temperature, the temperature-induced micellization and gelation of PX were also explored using differential scanning calorimetry and rheology. The incorporation of BSA had no discernible effect on critical micellization temperature (CMT), but it did affect gelation temperature (Tgel) and gel integrity of PX-based systems. The response surface approach illustrated the linear relation between the compositions and the CMT. The major factor affecting the CMT of the mixtures was the concentration of PX. The alteration of the Tgel and the gel integrity were discovered to be a consequence of the intricate interaction between PX and BSA. BSA mitigated the inter-micellar entanglements. Hence, the addition of BSA demonstrated a modulating influence on Tgel and a softening effect on gel integrity. Understanding the influence of serum albumin on the self-assembly and gelation of PX will enable the creation of thermoresponsive drug delivery and tissue engineering systems with controlled gelation temperatures and gel strength.

PO-03-063 A POLYACRYLAMIDE (PAA) GEL PHANTOM FOR STUDYING CATHETER ABLATION

Benchtop studies are often used to evaluate cardiac ablation techniques, and commonly utilize ex-vivo animal tissues. While widely available, ex-vivo animal tissues do not consistently replicate live atrial tissue physical properties, adding variability. Tissue mimicking phantoms have been used in non-cardiac ablation studies, but their mechanical and electrical properties may not mimic cardiac tissue. Furthermore, analysis of ablation lesions ex-vivo has been limited to 2D measurements of lesion cross-sections, precluding lesion volume measurement and limiting accuracy. Polyacrylamide (PAA) gels, which have modifiable elasticity, and similar thermal and electrical properties to live human tissues, have been used to study liver ablation. The addition of bovine serum albumin (BSA) – a protein that coagulates when heated beyond a set temperature – has also been shown to provide optical and MRI contrast in ablated gels. The aim of this study was to develop a reproducible atrial tissue phantom with realistic elasticity, friction, and electrical impedance, enabling in-vitro replication of cardiac ablation lesions and 3D quantification using high resolution MRI scans. Gels were mixed with acrylamide concentrations from 3% to 12% (g/mL) and 2% BSA. Resulting Young's moduli and coefficients of friction were measured with a custom tester. Reference frictional properties of ex-vivo porcine aortic specimens were measured using the same methods. Reference elasticity values were derived from the literature. Gels were ablated in saline with 20-40W of power, for 20-40s, with 10-20g of contact force. Baseline impedances were set to 125Ω by titrating the salinity of the bath. Finally, gels were imaged using a 3D T2-weighted sequence on a 3T MRI scanner. The elasticity and friction of the fabricated gels are reported in Table 1, along with reference values. 10.5-12% acrylamide PAA gel phantoms matched live contractile tissue elasticity, and simulated realistic atrial tissue frictional and electrical properties. Ablations were made optically visible by the coagulation of coagulated BSA (Fig 1a) and appeared hypointense on T2-MRI (Fig 1b), enabling automated 3D analysis by thresholding. Measured lesion dimensions were comparable to those reported in prior literature. PAA gel phantoms enabled in-vitro replication of cardiac lesions with realistic mechanical and electrical properties. The addition of BSA facilitated optical verification of lesions and 3D quantification using MRI.Tabled 1Table 1: Reference and measured physical properties of gel phantoms and ex-vivo aortae as compared to literature valuesPhysical PropertyReferenceMeasured ValueMaterialValueMaterialValueYoung's Modulus (kPa)Ex-vivo porcine left atrium28.0% PAA gel32.6In-vivo human left ventricle20-200.210.5% PAA gel68.1In-vivo skeletal muscle6.2-108.612.0% PAA gel108.0Coefficient of FrictionEx-vivo porcine aorta0.02-0.046Ex-vivo porcine aorta0.058±0.024Agarose gel0.03510.5% PAA gel0.023±0.0014 Open table in a new tab

The Effect of Bovine Serum Albumin on Benzo[a]pyrene Removal by Lactobacillus Strains.

The aim of this study was to investigate the influence of bovine serum albumin (BSA) on the Lactobacillus-strain-mediated removal of benzo[a]pyrene (BaP). A combination of 0.5 mg/mL of BSA with 1.0 × 1010 CFU/mL bacterial cells had a removal of 49.61% BaP for strain 121, while a combination of 0.4 mg/mL of BSA with 1.0 × 1010 CFU/mL bacterial cells had a removal of 66.09% BaP for strain ML32. The results indicated that the binding of BaP to Lactobacillus-BSA was stable. BSA maintains Lactobacillus activity and BaP removal in the gastrointestinal environment. Heat and ultrasonic treatment of BSA reduced the BaP-binding ability of Lactobacillus-BSA. With the addition of BSA, the surface properties of the two strains affected BaP binding. The Fourier-transform infrared (FTIR) data demonstrated that O-H, N-H, C=O, and P=O groups were involved in the binding of BaP to Lactobacillus-BSA. Scanning electron microscopy (SEM) results revealed that the morphology of Lactobacillus-BSA bound to BaP was maintained. The adsorption of BaP by Lactobacillus-BSA was appropriately described by the pseudo-second-order kinetic model and Freundlich isotherm model. BSA enhances the affinity between the bacterial cells and BaP.

Glucose Biosensor Based on Glucose Oxidase Immobilized on BSA Cross-Linked Nanocomposite Modified Glassy Carbon Electrode

Glucose sensors based blood glucose detection are of great significance for the diagnosis and treatment of diabetes because diabetes has aroused wide concern in the world. In this study, bovine serum albumin (BSA) was used to cross-link glucose oxidase (GOD) on a glassy carbon electrode (GCE) modified by a composite of hydroxy fullerene (HFs) and multi-walled carbon nanotubes (MWCNTs) and protected with a glutaraldehyde (GLA)/Nafion (NF) composite membrane to prepare a novel glucose biosensor. The modified materials were analyzed by UV-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), and cyclic voltammetry (CV). The prepared MWCNTs-HFs composite has excellent conductivity, the addition of BSA regulates MWCNTs-HFs hydrophobicity and biocompatibility, and better immobilizes GOD on MWCNTs-HFs. MWCNTs-BSA-HFs plays a synergistic role in the electrochemical response to glucose. The biosensor shows high sensitivity (167 μA·mM-1·cm-2), wide calibration range (0.01-3.5 mM), and low detection limit (17 μM). The apparent Michaelis-Menten constant Kmapp is 119 μM. Additionally, the proposed biosensor has good selectivity and excellent storage stability (120 days). The practicability of the biosensor was evaluated in real plasma samples, and the recovery rate was satisfactory.

Oxidative stress and DNA fragmentation in frozen/thawed common Carp Cyprinus carpio sperm with and without supplemental proteins

Using cryopreservation techniques can increase the effectiveness of reproducing cultured fish species by ensuring a dependable supply of sperm, although the quality of the sperm could be impacted by the procedures involved. The goal of this study was to investigate the effect of purified seminal plasma transferrin (Tf), bovine serum albumin (BSA), and antifreeze protein (AFP) types I and III at 1 µg mL−1 on relevant characteristics of cryopreserved sperm from common carp Cyprinus carpio. We compared oxidative stress indices, antioxidant activity, and DNA fragmentation of fresh sperm to that frozen with extender only or with Tf, BSA, or AFP types I and III. Fresh sperm had significantly lower levels of thiobarbituric acid reactive substances (TBARS) compared to samples that underwent cryopreservation without protein treatment, which resulted in 0.54 ± 0.06 nmol/108 cells of TBARS. Carbonyl derivatives of proteins (CP) decreased significantly (ANOVA; P > 0.05) in carp sperm with addition of Tf, AFPI, and AFPIII. Significant differences in superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPx) activity were seen in sperm supplemented with Tf, BSA, AFPI, and AFPIII from those without. Significantly less DNA damage, expressed as percent tail DNA (11.56 ± 1.34) and olive tail moment (0.59 ± 0.13), was recorded in samples cryopreserved with Tf. The findings indicated that addition of Tf, BSA, AFPI, or AFPIII to cryopreservation medium is beneficial to sperm preservation. The mechanisms through which these proteins act positively on sperm need to be further investigated.

Bovine serum albumin functional graphene oxide membrane for effective chiral separation

An efficient chiral separation membrane was fabricated from bovine serum albumin (BSA) modified graphene oxide (GO), BSA was linked with GO through EDC/NHS coupling chemistry. This BSA modified membrane can successfully separate Phe racemate, and the excess enantiomer (ee) in osmotic solution was up to 96.1% under the optimal conditions. We found that the addition of BSA not only enlarged the spacing but also formed chiral channels in the membrane to selective transport of L-Phe, enabling the chiral membrane to have both high flux and high selectivity. Further, we confirmed that the microstructure of BSA plays an important role in the chiral separation performance of the membrane. When the helical structure and globular three-dimensional structure of BSA are unfolding due to temperature rise, the chiral separation performance of the membrane will be weakened or even disappear. Addition, molecular docking simulation experiments also proved the reliability of this conclusion.

Effects of Different Concentrations of BSA on In Vitro Corrosion Behavior of Pure Zinc in Artificial Plasma

When medical metallic materials are implanted in the body and come into contact with the body fluid environment, proteins will be rapidly adsorbed on the surface and affect the corrosion process of the material. Currently, there is no uniform understanding of the effect of protein adsorption on the corrosion behavior of materials due to the limitations of the nature of metal materials, protein concentrations, and different media environments. The effect of various bovine serum albumin (BSA) concentrations in artificial plasma (AP) on the corrosion behavior of pure Zn during 14 days of immersion was investigated in this research. The corrosion rate of pure Zn was slowed down by the addition of BSA, and the decelerating effect of lower protein concentration on the corrosion rate of Zn was more significant in the initial stage of immersion. With prolonging the immersion time, the corrosion rate of pure Zn in different media slowed down and stabilized, and the corrosion rates of pure Zn showed a decreasing trend with an increase of BSA concentration. Furthermore, the Langmuir adsorption isotherm model was utilized to study the relationship between the BSA concentration and corrosion behavior of pure Zn and to analyze the role of proteins in the degradation mechanism of pure Zn. This work could be useful for further exploration of potential clinical applications of zinc alloys.

Revealing enzymatic digestibility of kraft pretreated larch based on a comprehensive analysis of substrate-related factors

The high degree of lignification in larch shows strong recalcitrance for its enzymatic digestibility to produce fermentation sugars for the further bio-energy production. Hence, pretreatment with excellent delignification ability should be carried out for larch. In this work, a high delignification degree of 77.3% could be achieved for larch after kraft pretreatment, while it still had a low enzymatic digestibility (30.3%), which was due to the remained stout cell wall structure revealed by confocal laser scanning microscopy. To elucidate the reason for low enzymatic digestibility, the addition of bovine serum albumin (BSA) and ball-milling were performed to investigate the substrate-related inhibiting factors of lignin and cellulose, respectively. It is found that the enzymatic digestibility of pretreated larch was enhanced to 58.8% by the addition of BSA, which is due to the reduction of the non-productive binding between residual lignin and cellulases. In addition, ball-milled could disrupt the cellulose's crystalline structures, which enhance the enzymatic hydrolysis of BSA-absorbed larch to 77.7%. This result indicated that cellulose structure is another inhibition bastion towards enzymatic digestion. This work revealed the effect of substrate-related factors that restrict the enzymatic digestibility of larch.

Cryopreservation of Sperm from an Endangered Snake with Tests of Post-Thaw Incubation in Caffeine.

Simple SummaryCryopreservation of sperm from reptiles to aid the recovery of endangered species continues to be a challenge. In this study, we tested the cryoperformance of a cryoprotective agent (CPA) mixture to cryopreserve sperm from the endangered Louisiana pinesnake (Pituophis ruthveni). The mixture contained Lake’s buffer with 10% N,N-dimethyl formamide (DMF), 2% methanol, 5% clarified egg yolk, (v/v% final concentration) and was tested against 16 experimental mixtures containing variable concentrations and mixtures of diluents, extenders, CPAs, and additives. In addition, we investigated the effects of post-thaw incubation on sperm motility in TL HEPES supplemented with 10% fetal bovine serum (H10) alone or supplemented with caffeine. We found that the majority of our test additives did not significantly improve the post-thaw motility or viability of sperm. The best performing experimental CPA mixture contained Lake’s buffer with 10% DMF, 2% methanol, and 5% clarified egg yolk with the addition of 5 mg/mL bovine serum albumin (BSA), and post-thaw incubation in both H10 and H10 with caffeine showed improved forward motility. Cryopreservation of sperm from the Louisiana pinesnake improved with the addition of BSA to our base CPA mixture, and post-thaw incubation in H10 improved with caffeine.Cryopreservation of sperm to preserve the genetic diversity of declining populations is a promising technique to aid in the recovery of endangered species such as the Louisiana pinesnake (Pituophis ruthveni). However, this technique has been performed on only a handful of snake species and with limited success. Here, we tested a cryoprotective agent (CPA) mixture containing Lake’s buffer with 10% N,N-dimethyl formamide (DMF), 2% methanol, 5% clarified egg yolk, (v/v% final concentration) against 16 other CPA-treatment mixtures. These contained either Lake’s buffer or TEST egg yolk buffer as the base diluent with a penetrating or non-penetrating CPA on the post-thaw recovery of sperm motility and viability. We also investigated the effect of post-thaw incubation treatment in TL HEPES supplemented with 10% fetal bovine serum (H10) alone or with caffeine on post-thaw motility parameters. Sperm from 16 Louisiana pinesnakes was cryopreserved, and the effectiveness of the CPA treatment mixtures and post-thaw treatments was determined based on measurements of sperm motility and viability. Sperm cryopreservation significantly reduced initial post-thaw sperm quality for all of the extender treatments. Viability of sperm was best maintained when cryopreserved in an CPA treatment mixture containing Lake’s buffer with 10% DMF, 2% methanol, and 5% clarified egg yolk with the addition of 5 mg/mL bovine serum albumin (BSA). For several extender mixtures a similar percent of post-thaw motility was observed, but no forward motility returned in any post-thaw samples prior to incubation in dilution treatments. Following incubation in both post-thaw treatments, the percent of forward motility and the index of forward progressive movement improved significantly. Post-thaw dilution with H10 containing caffeine improved motility parameters over H10 alone, suggesting further investigation of post-thaw treatment in caffeine could be beneficial. Although, cryopreservation of sperm from the Louisiana pinesnake continues to present a challenge, post-thaw dilution and the addition of BSA to CPA mixtures provides areas for improving cryopreservation methods for this endangered species.

Bovine Serum Albumin Adsorption at a Polarized Water/1,2‐Dichloroethane Interface with No Effect on the Ion Transfer Kinetics

AbstractAdsorption of bovine serum albumin (BSA) at a polarized water/1,2‐dichloroethane (DCE) interface is examined by measuring the dynamic interfacial tension at various cell potentials E, BSA concentrations and pH of the aqueous phase (w). An addition of BSA to the phase (w) results in an appreciable decay of with time in the whole potential range available, which follows an induction period at the very beginning of the transient. An analysis of the effect of the BSA concentration on the transients enables to establish the adsorption isotherm, and to evaluate both the maximum surface excess concentration of BSA and the standard Gibbs energy of adsorption. An increase of the potential E results in an acceleration of the adsorption, and an increase of the surface excess concentration of the positively charged BSA at pH 2, while the latter effect is absent when BSA is charged negatively at pH 7.3. It is shown that the adsorbed BSA has a negligible effect on both the interfacial capacitance of the polarized water/DCE interface and the rate constant of the interfacial transfer of the tetraethylammonium (TEA+) or Cs+ ion measured at the corresponding standard ion transfer potential.

Development of an effective method of human DNA extraction from soil as forensic evidence

In forensic investigations, it is crucial to detect a suspect’s DNA from the available evidence. In an outdoor crime scene, the evidence may be mixed with the soil. However, soil is speculated to inhibit DNA extraction from forensic science samples. In the field of soil microbiology, it is necessary to extract DNA directly from soil to analyse its microbial composition. In this study, we investigated whether skim milk used in procedure of DNA extraction from soil samples could be applied to forensic science to enhance human DNA extraction efficiency from soil mixed with forensic evidence, such as blood, buccal cells, and skin cells. The use of additive reagents, skim milk and bovine serum albumin (BSA), are known to blocking reagent. In the selection of additive reagents experiment, about blood sample, using the skim milk and BSA were found to increase the DNA yield. Therefore, we observed extracted DNA yield from blood, buccal cells, and skin cells when skim milk and BSA were used as additive reagents. The DNA recovery rate was high across all samples upon addition of skim milk. However, in STR analysis, a non-specific peak was detected in the extracted DNA in the presence of skim milk, which was not detected in the presence of BSA, indicating its suitability in forensic analysis. Our study suggests that addition of BSA can efficiently aid the extraction of DNA from forensic evidence mixed with soil.

Turn-on fluorescence probe for BSA detection and selective cell imaging

In this paper, a cationic amphiphile (denoted by DPP-10) with diketopyrrolopyrrole decorated with methoxylated tetraphenylethylene via a phenyl bridge was designed, synthesized, and applied as a turn-on fluorescence probe for bovine serum albumin (BSA) detection and selective cell imaging. DPP-10 showed very weak fluorescence emission when dispersed in the solution, while its emission was drastically enhanced upon the addition of BSA, which should be attributed to the electrostatic interaction-driven assembly between DPP-10 and BSA. The limit of detection was as low as 0.08 μmol/L, which is lower than that reported for most probes. The fluorescence probe shows good selectivity for BSA among the tested proteins, high photostability, and immunity to the disturbance of ions. DPP-10 with excellent cytocompatibility was applied to HeLa cell imaging, where only the BSA-rich cells showed a strong signal-to-background contrast.