I agree with María Luisa Caballero . Histopaque and Ficoll-Paque both contain polysucrose and sodium diatrizoate, adjusted to a density of 1.077g/mL. They are ready-to-use medium that facilitate rapid recovery of viable lymphocytes and other mononuclear cells from small volumes of whole blood.
Yes, you can follow the same method of extraction using these solutions for PBMC isolation.