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  2. McFarland standards - Wikipedia

    en.wikipedia.org/wiki/McFarland_standards

    Mixing the two compounds forms a barium sulfate precipitate, which causes turbidity in the solution. A 0.5 McFarland standard is prepared by mixing 0.05 mL of 1.175% barium chloride dihydrate (BaCl 2 •2H 2 O), with 9.95 mL of 1% sulfuric acid (H 2 SO 4 ).

  3. Phosphate-buffered saline - Wikipedia

    en.wikipedia.org/wiki/Phosphate-buffered_saline

    There are many different ways to prepare PBS solutions, common ones are Dulbecco's phosphate-buffered saline (DPBS) [2] and the Cold Spring Harbor protocol. [3] Some formulations of DPBS do not contain potassium and magnesium, while other ones contain calcium and/or magnesium (depending on whether or not the buffer is used on live or fixed tissue: the latter does not require CaCl 2 or MgCl 2).

  4. Sulfuric acid - Wikipedia

    en.wikipedia.org/wiki/Sulfuric_acid

    Although nearly 100% sulfuric acid solutions can be made, the subsequent loss of SO 3 at the boiling point brings the concentration to 98.3% acid. The 98.3% grade, which is more stable in storage, is the usual form of what is described as "concentrated sulfuric acid".

  5. Equivalent concentration - Wikipedia

    en.wikipedia.org/wiki/Equivalent_concentration

    If the concentration of a sulfuric acid solution is c(H 2 SO 4) = 1 mol/L, then its normality is 2 N. It can also be called a "2 normal" solution. It can also be called a "2 normal" solution. Similarly, for a solution with c (H 3 PO 4 ) = 1 mol/L, the normality is 3 N because phosphoric acid contains 3 acidic H atoms.

  6. Reference electrode - Wikipedia

    en.wikipedia.org/wiki/Reference_electrode

    3) Acid solution with an activity of H + = 1 mol/L, 4) Hydroseal for prevention of oxygen interference, 5) Reservoir via which the second half-element of the galvanic cell should be attached. The connection can be direct, through a narrow tube to reduce mixing, or through a salt bridge, depending on the other electrode and solution. This ...

  7. Standard solution - Wikipedia

    en.wikipedia.org/wiki/Standard_solution

    In titrations, the concentration of analyte in solution can be determined by titrating the standard solution against the analyte solution to determine the threshold of neutralization. [9] For example, to calculate the concentration of hydrogen chloride, a standard solution of known concentration, such as 0.5 M sodium hydroxide, is titrated ...

  8. McIlvaine buffer - Wikipedia

    en.wikipedia.org/wiki/McIlvaine_buffer

    McIlvaine buffer is a buffer solution composed of citric acid and disodium hydrogen phosphate, also known as citrate-phosphate buffer.It was introduced in 1921 by the United States agronomist Theodore Clinton McIlvaine (1875–1959) from West Virginia University, and it can be prepared in pH 2.2 to 8 by mixing two stock solutions.

  9. Kjeldahl method - Wikipedia

    en.wikipedia.org/wiki/Kjeldahl_method

    The sample solution is then distilled with a small amount of sodium hydroxide (NaOH). [3] NaOH can also be added with a dropping funnel. [4] NaOH reacts the ammonium (NH 4 +) to ammonia (NH 3), which boils off the sample solution. Ammonia bubbles through the standard acid solution and reacts back to ammonium salts with the weak or strong acid. [3]