Assessment of DNA contamination from dried blood spots and determination of DNA yield and function using archival newborn dried blood spots.
BACKGROUND
Residual dried blood spots (DBS) from newborn screening programs are often stored for years and are sometimes used for epidemiological studies. Because there is potential for DNA cross-contamination from specimen-to-specimen contact, we determined contamination levels following intentional contact and assessed archival DBS DNA degradation after storage in an uncontrolled environment.


METHODS
DBS from healthy adult females were rubbed with DBS from healthy or cystic fibrosis (CF)-affected adult males. Total human and male DNA was measured from the female DBS. Contamination levels were assessed using short tandem repeats (STRs). Female DBS contaminated with CF male DNA containing the F508del were analyzed for presence of this mutation. Archival DBS DNA amplification efficiency was determined using STR analysis.


RESULTS
Most female DBS were contaminated, however only one specimen showed an incomplete STR profile consistent with contaminating CF-affected male DNA. Further testing by CF mutation screening was negative. DNA extracted from archival DBS showed robust amplification (range 100 bp-320 bp).


CONCLUSIONS
Lightly abrasive contact between DBS resulted in DNA cross-contamination. The contaminating DNA did not interfere in CF-mutation tests; however this should be determined for individual assays. Since DNA from archival DBS robustly amplifies, newborn DBS could provide an invaluable resource for public health studies.
Cordovado
Suzanne K
SK
Centers for Disease Control and Prevention, Division of Laboratory Sciences, National Center for Environmental Health, Atlanta, Georgia 30341, United States. snc4@cdc.gov
Earley
Marie C
MC
Hendrix
Miyono
M
Driscoll-Dunn
Rena
R
Glass
Michael
M
Mueller
Patricia W
PW
Hannon
W Harry
WH
D000328:Adult; D001483:Base Sequence; D001771:Blood Banks; D003550:Cystic Fibrosis / Q000097:blood* / Q000235:genetics; D004247:DNA / Q000097:blood* / Q000302:isolation & purification; D004249:DNA Damage; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013048:Specimen Handling
D004247:DNA