The page below is a sample from the LabCE course Introduction to Flow Cytometry: Blood Cell Identification. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Introduction to Flow Cytometry: Blood Cell Identification (online CE course) »
How to Subscribe
MLS & MLT Comprehensive CE Package
Includes 94 CE courses, most popular
$95 Add to cart
Pick Your Courses
Up to 8 CE hours
$50 Add to cart
Individual course$20 Add to cart

Calculating Absolute Cell Counts- continued

Now that the absolute lymphocyte value has been calculated, the results from the flow cytometric analysis can be incorporated as follows:

Values from the flow cytometer analysis

  • %CD3= 60% (CD3 positivity reflects total T cell percentage)
  • %CD4= 40% (CD4 positivity reflects T-helper cell percentage)
  • %CD8= 20% (CD8 positivity reflects cytotoxic T cell percentage)

*Note that 60% CD3 (total mature T cells) is further broken down into 40% CD4 (T-helper cells) + 20 % CD8 (cytotoxic T cells)

By using the following calculation, the absolute (Abs) cell CD marker populations = Abs lymphocytes x % CD (as decimal)

For Example:

AbsCD3= 750 x 0.60 = 450 cells/mcL

AbsCD4= 750 x 0.40 = 300 cells/mcL

AbsCD8= 750 x 0.20 = 150 cells/mcL

CD4:CD8 ratio= 40/20 = 2.0