Please review the protocol at the link below:
https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/documents/176/154/mak242bul.pdf
This kit is not intended for use in flow cytometry. A typical measurement is done on a plate reader like those presented in the link below:
https://www.sigmaaldrich.com/substance/benchmarksmartreader96microplateabsorbancereaderwithincubation1234598765
To discuss further, please navigate to the link https://www.sigmaaldrich.com/techservice, and click on "Product Technical Inquiries" under the Products Section with all the required information so that a member of the Technical Service team can reach out to assist further. Thank you.