Hypotonic Saline to Phenotype Multiply Transfused Sickle Cell Patient

Nowadays, if we have a multiply transfused patient with a complex antibody pattern, we might resort to RBC genotyping to help us resolve the antibody issues.  Fortunately, there is one situation where we can quickly phenotype the patient by using hypotonic saline to lyse the transfused RBCs since the sickle cells are resistant.

The results can be quite clean and easy to interpret as in the following example using 0.4% saline:

It is a lot cheaper to make dilute saline than an RBC genotype—and much quicker!