Results of microfluidic chip technology using SEP buffer were comparable to those of SDS-PAGE and previously reported data.

No abstract

No abstract

This work presents the electrophoretic profile of goat and cow milk samples and their mixtures using microfluidic and conventional electrophoresis. The microfluidic method allowed the separation of the major caseins from milk, excepting the goat κ-casein.  Besides, the major whey proteins were separated with perfect distinction of A and B β-lactoglobulin variants. Comparing to SDS-PAGE, a variation in the molecular weight was observed in all milk proteins. However, A and B β-lactoglobulin variants could not be isolated using SDS-PAGE. Although urea-PAGE did not show high resolution among whey proteins, γ-, κ-, β-, and α-caseins were clearly identified. This method also showed a lower limit detection of cow milk in mixture samples than the "lab-on-a-chip" electrophoresis. In both methods, the highest linearity obtained from plotting total percentage against cow milk concentration was observed by using cow αs1-casein (R2 = 0.986 and R² = 0.973). This result indicates that microfluidic electrophoresis is an effective tool to detect the presence of some proteins in goat and cow milk, and in mixtures. Microfluidic chip technology might will complement the current methods for analyzing milk proteins, highlighting its speed amount of reagents and whey protein separation, which showed a better result than urea or SDS-PAGE

In the present study, lab-on-a-chip electrophoresis (LoaC) was suggested as an alternative method to the conventional polyacrylamide gel electrophoresis under denaturing conditions (SDS-PAGE) to analyze raw cell-free tick hemolymph. Rhipicephalus microplus females were exposed to the entomopathogenic fungus Metarhizium anisopliae senso latu IBCB 116 strain and/or to the entomopathogenic nematode Heterorhabditis indica LPP1 strain. Hemolymph from not exposed or exposed ticks was collected 16 and 24 h after exposure and analyze by SDS-PAGE or LoaC. SDS-PAGE yielded 15 bands and LoaC electrophoresis 17 bands. Despite the differences in the number of bands, when the hemolymph protein profiles of exposed or unexposed ticks were compared in the same method, no suppressing or additional bands were detected among the treatments regardless the method (i.e., SDS-PAGE or chip electrophoresis using the Protein 230 Kit®). The potential of LoaC electrophoresis to detect protein bands from tick hemolymph was considered more efficient in comparison to the detection obtained using the traditional SDS-PAGE method, especially when it comes to protein subunits heavier than 100 KDa. LoaC electrophoresis provided a very good reproducibility, and is much faster than the conventional SDS-PAGE method, which requires several hours for one analysis. Despite both methods can be used to analyze tick hemolymph composition, LoaC was considered more suitable for cell-free hemolymph protein separation and detection. LoaC hemolymph band percent data reported changes in key proteins (i.e., HeLp and vitellogenin) exceptionally important for tick embryogenesis. This study reported, for the first time, tick hemolymph protein profile using LoaC.