Controls for Flow Cytometry & Sample Storage
It is good practice to use controls to ensure the specificity of an experimental setup.
For FC these controls can be negative as well as positive.
Negative controls (better-named isotype controls) are made up of a primary antibody with no reactivity with the cell type under investigation. This antibody must be of the same isotype, have the same fluorochrome, the same concentration, and F/P (fluorochrome/protein) ratio as the relevant antibody of interest. The purpose is to evaluate the degree of antibodies to these cells.
A common source of sample for FC analysis in peripheral blood (PB) or bone marrow (BM). Circulating cells removed from their natural environment will have a limited lifetime, and specifically, the proteins expressed will start to deteriorate within a few hours.
To prevent this, it is advisable to perform the analysis immediately. If this is not possible, there are excellent procedures and products for storing samples and preserving proteins intact for prolonged periods of time.
Read more about Flow Cytometry here.