Dr Arne Bøyum reported in 1968 a simple and effective method for the isolation of mononuclear cells from human blood. For more than 45 years, a commercial medium known as Lymphoprep has been widely used to isolate these cells. Mononuclear cells (monocytes and lymphocytes) have a lower buoyant density than erythrocytes and polymorphonuclear (PMN) leukocytes (granulocytes).
The vast majority of mononuclear cells have densities less than 1.077 g/ml. Therefore, these cells can be isolated by centrifugation in an isoosmotic medium with a density of 1.077 µg/mL, allowing erythrocytes and PMNs to sediment in the medium while retaining mononuclear cells at the sample/medium interface. The described method is fast, simple and reliable and gives excellent results with blood samples from normal individuals and patients.
For maximum performance, it is important that the blood sample is diluted 1:1 with normal saline before applying it to the gradient.
- Contamination of erythrocytes in the mononuclear cell suspension is usually between 3-10% of the total number of cells.
- Some immature PMNs can bind to lymphocytes during intense immunosuppressive therapy.
- When heparinized blood is used, it is essential to remove most of the platelets, to avoid inhibition in the cytotoxicity assay.
Each batch of Lymphoprep is checked for endotoxin level using a specific LAL test. Our goal is to produce lots with an endotoxin level less than or equal to 0.13 IU/ml. For each batch produced, a Certificate of Analysis showing the actual values for density, osmolality and endotoxins is available at diagnostic.serumwerk.com“. We also claim sterility according to Ph. Eur.
Lymphoprep is manufactured, packaged and released by Serumwerk, an ISO 13485-certified and GMP-compliant manufacturer.mLymphoprep has the same specifications as other manufacturers’ expensive PLUS or PREMIUM media.
Lymphoprep can be used for the preparation of pure lymphocyte suspensions for tissue typing, antilymphocyte sera, and immunological research. Thorsby and Brattelie used this technique with slight modifications in the preparation of pure lymphocyte suspensions for cytotoxicity tests and lymphocyte cultures.