This makes parallel dilution impractical as the necessary volume of the stock solution would be too small to accurately measure. However, in some situations, the dilution factor, which is equal to the final volume divided by volume of stock solution needed for the dilution, is too large.
The resulting volume can be diluted to the total volume of the solution to achieve the desired concentration. Using this simple calculation, a solution of desired concentration and desired volume can be prepared from a stock solution of known concentration.
These stock solutions can be diluted as necessary with solvent to achieve the desired concentration.Īlternatively, a dilution can be prepared from a more concentrated solution using a parallel dilution. Stock solutions may be labeled as a multiple of the concentration in the final working solution. In this case, the percent concentration can be expressed as the volume of liquid solute per unit volume of solvent, referred to as a percent volume-volume solution.įor frequent use, concentrated solutions of stable compounds, known as stock solutions, can be prepared. Keep in mind that the solute is sometimes in liquid form. Solutions can also be prepared and quantified as percent concentrations from the weight of solute per unit volume of solvent, known as a percent weight-volume solution. When making solutions in the lab, the mols of solute can be determined from the measured mass of the molecule and its molecular weight. A one molar solution contains one mol of solute per liter of solution (B+C). When performing experiments, it is imperative to know the exact concentration of solutions used.Ĭoncentration is most commonly expressed as molarity.
Use of a serial dilution to prepare standards for generating a standard curve in protein quantitation is also demonstrated. Gel electrophoresis is a commonly used laboratory procedure which requires preparation of a percent weight volume solution as well as parallel dilution of a concentrated stock solution. Some applications for measuring volumes are then presented.
For example, the video reviews how to measure volumes with precision through use of the appropriate volumetric container as well as how to read the volume when a meniscus is present. This video also lays a foundation for the accurate preparation of solutions. Concentrated solutions are diluted through various methods, such as serial dilution. Solutions are generally identified by their components and corresponding concentrations.
Solutions consist of a solute dissolved in solvent to yield a homogeneous mixture of molecular substances. In this video, concepts in preparing solutions are introduced. Therefore understanding how to measure and manipulate them is imperative to any experiment. Solutions are utilized to some degree in almost all biological research applications.