{"id":2869,"date":"2026-10-03T03:43:46","date_gmt":"2026-10-03T03:43:46","guid":{"rendered":"https:\/\/nhdbio.com\/?p=2869"},"modified":"2026-10-15T03:30:39","modified_gmt":"2026-10-15T03:30:39","slug":"%e8%82%bd-mg-%e5%88%b0-nmol-%e8%ae%a1%e7%ae%97%e6%8c%87%e5%8d%97","status":"publish","type":"post","link":"https:\/\/nhdbio.com\/cn\/peptide-mg-to-nmol-calculation-guide\/","title":{"rendered":"\u57281 mg\u80bd\u4e2d\u6709\u591a\u5c11\u4e2anmol\uff1f\u4e00\u4e2a\u5b8c\u6574\u7684\u6362\u7b97\u793a\u4f8b"},"content":{"rendered":"

A vial says 1 mg, but the paper you are reading uses nmol. How do you compare them? You need one more number: the peptide\u2019s molecular weight. Here is why, followed by a calculation you can repeat with your own figures.<\/p>\n

What is the difference between mg and nmol?<\/h2>\n

Imagine weighing a handful of small beads and a handful of large beads. At the same weight, you will usually have more small beads. Peptide molecules follow the same idea: equal milligrams do not necessarily mean equal numbers of molecules.<\/p>\n

A nanomole, written nmol, is a unit for an amount of molecules. Molecular weight, usually listed in g\/mol for these calculations, connects that amount to its weight.<\/p>\n

\"Figure
Figure 1. Find the molecular weight before converting mg to nmol.<\/figcaption><\/figure>\n

Work through 1 mg of an example peptide<\/h2>\n

Use an example molecular weight of 2,000 g\/mol. This is a round number for practice. Convert the sample mass to grams, divide by the molecular weight, then convert mol to nmol.<\/p>\n

    \n
  1. 1 mg = 0.001 g.<\/li>\n
  2. 0.001 \u00f7 2,000 = 0.0000005 mol.<\/li>\n
  3. Multiply by 1,000,000,000: the result is 500 nmol.<\/li>\n<\/ol>\n

    1 mg \u00d7 1,000,000 \u00f7 2,000 = 500 nmol<\/p>\n

    Why another 1 mg vial gives a different answer<\/h2>\n

    Keep the mass at 1 mg. If the molecular weight is 1,000 g\/mol, you get 1,000 nmol. At 4,000 g\/mol, you get 250 nmol. Each heavier molecule takes up a larger share of that 1 mg.<\/p>\n

    This is why a conversion for one peptide cannot simply be copied to another.<\/p>\n

    \"Figure
    Figure 2. Three example molecular weights give three different amounts from 1 mg.<\/figcaption><\/figure>\n

    Does the vial\u2019s powder weight equal peptide weight?<\/h2>\n

    Not always. A powder may also contain water and salt components. Dividing the total powder weight by the peptide\u2019s molecular weight gives an estimate based on powder weight, rather than a measured amount of the target peptide.<\/p>\n

    If a laboratory has measured the target peptide\u2019s mass fraction, that result can support a correction. An HPLC purity percentage alone does not tell you that mass fraction.<\/p>\n

    \"Figure
    Figure 3. Powder weight and measured target-peptide weight answer different questions.<\/figcaption><\/figure>\n

    Try 0.5 mg yourself<\/h2>\n
    At 2,500 g\/mol, how many nmol are in 0.5 mg?<\/strong><\/p>\n
    \nSee the answer<\/summary>\n

    0.5 \u00d7 1,000,000 \u00f7 2,500 = 200 nmol. Keep a note of which molecular weight and mass you used.<\/p>\n<\/details>\n<\/div>\n

    You can use the same formula for other values. If the answer is a thousand times too large or small, check mg versus g and nmol versus \u00b5mol first.<\/p>\n

    Converting quantities for MOTS-c or KPV<\/h2>\n

    When comparing MOTS-c and KPV, use the molecular weight for each exact product form. Check whether the stated quantity is total powder or a measured peptide amount. These two details make the conversion useful, rather than just a correct calculation.<\/p>\n

    MOTS-c<\/a> \/ KPV<\/a><\/p>\n

    Discuss material and document requirements with NHD<\/a> \u00b7 Continue with the analytical guide<\/a><\/p>\n