Tissue-Bank Blog Murashige and Skoog Without Nitrogen

Murashige and Skoog Without Nitrogen


The composition of the culture medium is crucial in all experiments that contain living organisms. The need for a well-balanced plant medium arose at the beginning of hydroponics and plant tissue cultures. The first recipes for plant tissue cultures are related to big names for in vitro plants: Hildebrandt et al. (eg Hildebrandt et al., 1946). Important research in the field of plant media was carried out in the 1960s and 1970s, probably the most important publication being Murashige and Skoog (1962). This medium was originally designed for nicotiana (Tobacco) calluses but is used in altered forms for other plants, eg the ubiquitous Arabidopsis thaliana.

Naturally, different plants require different media compositions, but today MS-based media is widely used for many species. However, there are also many exceptions, since plants are diverse organisms, eg Knudson’s media for orchids (Knudson, 1951; Sigma-Aldrich-a). The difference in composition with the common alternatives is mentioned below. In summary, they differ in the number of macronutrients (for example, some plants demand more nitrogen or phosphorus) but also in the presence of micronutrients, which determines some media only for short-term crops.


  • The main component of plant cultivation is in vitro.
  • Plant tissue culture media such as callus induction, shoot regeneration and root formation.
  • For the germination of seeds of different plant species such as Arabidopsis thaliana and Nicotiana benthamiana, under sterile growth conditions.


  • In the original study, an acidic solution (pH 5.7-5.8) is used (Murashige and Skoog, 1962)
  • Most known plant tissues require a pH of 5.2 to 5.8 (Skirvin et al., 1986).
  • The pH will be in constant flux during cultivation, so stable buffer conditions are essential for long-term cultivation. MES is commonly used because it buffers pH well between 5 and 7 (approximately) and is non-toxic to most plant species.
  • The medium is generally adjusted with NaOH/HCl. KOH can also be used instead of NaOH.


  • basal salts
  • vitamins
  • Buffering substance (MES)
  • Carbon resource (sucrose)
  • Reinforcing agent (agar)
  • NaOH/HCl for pH adjustment

Instruments and other requirements

  • Crystal glass
  • weighing scale
  • Magnetic stirrer and pellet
  • pH meter
  • measuring cylinders
  • Pipette
  • Autoclavable bottles


Using a balance, prepare exact amounts of basal salts, vitamins, sucrose, MES, and agar (for solid medium).


If you are preparing the MS from basic reagents, you can prepare a stock powder of basal salts and vitamins (well mixed).

  • Prepare ¾ of the final volume of distilled water in a beaker.
  • Put salts, vitamins, sucrose and MES to dissolve (Do not add agar yet!). A magnetic stirrer can be used.
  • After everything is dissolved, measure and adjust the pH.
  • Adjust the final volume using a measuring cylinder.
  • Transfer the liquid to bottles to autoclave and add agar (if you have more bottles, add a proportional amount of agar to each bottle).
  • Autoclave the bottles with media. An autoclave that is too long causes the degradation of some compounds.
  • After autoclaving, allow the bottles to cool slightly before pouring them into plates. Working with almost boiling liquid is not pleasant. Also, agar freezes at 30-35°C, so it can wait a bit after autoclaving.
  • Try to avoid working in a non-sterile environment – use a flow box.
  • If you want to add hormones/antibiotics, add them to the cooling medium. (The five-second rule is helpful here. If you can hold your hand for five seconds or more over the bottle, you can add labile compounds).
  • Now you can pour the medium into plates. Mix the bottle before each pour.

Solid media preparation

For solid medium, use agar or phytagel.

  • Agar: 5-10 g/l
  • Phytagel: 1.5-2.5 g/l


The universal storage condition is 4 °C. Store at this temperature the stock of basal salts and vitamins, prepared liquid media, and solid MS plates.


The MS medium is a safe medium. The main problems could be related to too long autoclaving (even caramelized sugar) and non-sterile working conditions (sugar is an optimal nutrient for bacteria and fungi).

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