Preparation of SM Buffer with gelatin (lambda diluent)


SM buffer with gelatin is a commonly used buffer solution for various cellular and biochemical applications. It is a versatile buffer that can be used for cell lysis, protein extraction, and as a stabilizing agent for cell suspensions. The preparation of SM buffer with gelatin involves mixing the following components in distilled water:


  • NaCl (150 mM)
  • MgSO4 (10 mM)
  • KCl (5 mM)
  • Na2HPO4 (10 mM)
  • KH2PO4 (10 mM)
  • Gelatin (0.5%)


  1. Dissolve 150 mM NaCl, 10 mM MgSO4, 5 mM KCl, 10 mM Na2HPO4, and 10 mM KH2PO4 in distilled water.
  2. Adjust the pH to 7.4 using NaOH or HCl.
  3. Sterilize the solution by filtration or autoclaving.
  4. Add 0.5% gelatin to the solution and mix until dissolved.
  5. Store the SM buffer with gelatin at 4°C.

Note: Gelatin should be added just before use, as it can cause the buffer to become turbid over time. Also, the concentration of gelatin can be adjusted depending on the specific application and requirements.

To prepare one liter follow this

To prepare 1 liter of SM buffer with gelatin, dissolve the NaCl and MgSO4·7H2O in 800 ml of H2O; add the Tris-Cl and gelatin; and adjust the volume to 1 liter with H2O. Sterilize the buffer by autoclaving for 20 minutes at 15 psi (1.05 kg/cm2) on a liquid cycle. After the solution has cooled, dispense 50 ml aliquots into sterile containers. SM buffer with gelatin may be stored indefinitely at room temperature. Discard each aliquot after use to minimize the chance of contamination. To prepare SM Buffer without gelatin click here and to prepare Tris-cl click here

ReagentAmountFinal concentration
NaCl5.8 g100 mM
MgSO4·7H2O2 g8 mM
Tris-Cl (1 M, pH 7.5)50 ml50 mM
Gelatin (2%, w/v)5 ml0.01% (w/v)
H2Oto 1 liter 
Table showing the ingredients to make one liter of SM buffer with gelatin
Prepared <a href=httpswwwgbiosciencescomBuffers Reagents ChemicalsMolecular Biology Related Buffers ChemicalsSM Buffer target= blank rel=noopener nofollow title=commercial SM BUFFER>commercial SM BUFFER<a>

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I'm Raphael Hans Lwesya, My true passion lies in the world of phage research and science communication. As a diligent phage researcher and an enthusiastic science communicator, I've founded "," a platform dedicated to unraveling the fascinating universe of bacteriophages – viruses that specifically target microbes. My ultimate mission is to bridge the communication gap between the general public and the often intricate world of scientific concepts. I take pride in simplifying complex ideas, breaking them down into easily understandable pieces, and making cutting-edge phage-related research accessible to a wide audience. Thank you for visiting The Phage blog. If you have got any question or suggestion please drop it as a comment or via [email protected]


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