Cell permeabilization and stabilization reagent and method of use

A sample mixture composition comprising:

• (a) a whole blood;
• and
• (b) a cell permeabilization and stabilization reagent comprising an aqueous solution of 0.1 mM to 10 mM of N-acyl sarcosine or a salt thereof represented by the following molecular structure:
• R1—CO—N(CH3)CH2COOX1
• wherein R1 is an alkyl or alkylene group having 8 to 18 carbon atoms, and X1 is H, Na+, or K+;
• said reagent having a pH between 4 and 6 and a conductivity less than 1.2 mS/cm;
• and
• wherein the cellular membrane of blood cells in said whole blood is permeated and intracellular proteins of said blood cells are caused to aggregate by said reagent, while said blood cells are preserved for cellular analysis.

A cell permeabilization and stabilization reagent comprising an aqueous solution of:

• (a) 0.1 mM to 10 mM of N-acyl sarcosine or a salt thereof represented by the following molecular structure:
• R1—CO—N(CH3)CH2COOX1
• wherein R1 is an alkyl or alkylene group having 8 to 18 carbon atoms, and X1 is H, Na+, or K+;
• and
• (b) saccharide or glycerol;
• said reagent having a pH less than 7 and a low ionic strength defined by a conductivity of less than 1.2 mS/cm;
• wherein said reagent enables permeation of the cellular membrane and causes aggregation of intracellular proteins of blood cells while preserving said blood cells for cellular analysis.