What Is IMDM? Iscove’s Modified Dulbecco’s Medium Explained

IMDM (Iscove’s Modified Dulbecco’s Medium) is a nutrient-rich basal medium built for fast-growing, high-density cultures, especially cells of the blood and immune system. It is a modification of DMEM developed by Nils Iscove for the culture of hematopoietic cells, and it remains a favorite for lymphocytes, bone marrow, and hybridomas. This guide explains what IMDM is, how it differs from DMEM, what it contains, and which cells it suits.

What is IMDM?

IMDM is a chemically balanced basal medium based on DMEM, but enriched to support demanding, rapidly dividing cells. Nils Iscove developed it while studying the growth of hematopoietic progenitor cells, which need a richer environment than standard media provide. Like other basal media, IMDM supplies salts, amino acids, vitamins, and glucose, and it is completed with serum (or a serum substitute) and glutamine before use.

How IMDM differs from DMEM

IMDM keeps DMEM’s high-glucose backbone but adds and adjusts several components:

• Extra amino acids, including additional non-essential amino acids, plus added vitamins
• Selenium and HEPES buffering built in alongside the bicarbonate buffer
• Potassium nitrate in place of ferric nitrate, and added sodium pyruvate

The result is a richer medium that supports higher cell densities and works well for reduced-serum and serum-free protocols. For the base medium it is built on, see our guide on DMEM.

What is IMDM used for?

IMDM is a go-to medium for blood-derived and rapidly proliferating cells, including:

• Hematopoietic and bone marrow cells, including progenitor and stem cell work
• Lymphocytes and B cells
• Hybridomas for antibody production
• Other high-density suspension and adherent cultures

What is in IMDM?

A typical IMDM formulation contains inorganic salts, a broad set of amino acids, a rich vitamin profile, high glucose, selenium, sodium pyruvate, and both a bicarbonate buffer and HEPES, along with phenol red as a pH indicator. Because it uses a bicarbonate buffer, IMDM is normally kept in a CO2 incubator (usually 5%), though its HEPES content gives it extra pH stability during handling.

How to supplement and use IMDM

Before use, IMDM is completed with serum (commonly 10% FBS) or a defined serum substitute, plus L-glutamine or a stable glutamine dipeptide. Keep it in a CO2 incubator to hold the correct pH, store it refrigerated and protected from light, warm it gently before use, and keep the same lot across an experiment for consistency. Its richness makes it especially useful when you are pushing cells to high density or moving toward reduced-serum culture.