Whole blood sample preparation for polymerase chain reaction using ammonium chloride and a carboxylic acid or metal carboxylate for selective red blood cell lysis

A method for the amplification and detection of a target nucleic acid comprising:

• I) selectively preparing leucocytes suspected of containing a target nucleic acid in a whole blood sample by:
• A) mixing a whole blood sample with an erythrocyte lysing solution comprising between 50 mM and 100 mM of ammonium chloride and between about 0.001 weight percent to about 0.1 weight percent of a monocarboxylic acid or salt thereof selected from the group consisting of acetic acid, monosubstituted acetic acid, disubstituted acetic acid and trisubstituted acetic acid, and wherein said lysing solution has a pH of between 6 and 8,
• B) centrifuging the resulting mixture to form a pellet of leucocytes from said whole blood sample,
• C) after removing the supernatant, washing said leucocyte pellet in a fresh sample of said lysing solution, and
• D) centrifuging and isolating said leucocyte pellet, provided that steps A) through D) are carried out within about 20 minutes,
• II) lysing the leucocytes in said washed pellet to release said target nucleic acid,
• III) amplifying said released target nucleic acid using polymerase chain reaction and a set of primers that are specific to and hybridizable with the opposing strands of said target nucleic acid, and
• IV) detecting said amplified target nucleic acid.