A Comparison Study On The New Formula of Bluestar® Latent Bloodstain Reagent and It’s Effects on DNA Typing/Amplification

OBJECTIVE: This study was designed to test two kinds of latent blood reagents, luminol and Bluestar® Magnum, and to determine their ability to detect latent blood and to preserve DNA for genetic profile determinations. DESIGN: Three dilutions of blood were applied to six substrates: vinyl tile, ceramic tile, treated and untreated wood, carpet and cinderblock. Each blood dilution, 1:1, 1:10 and 1:100, was cleaned with four cleaning agents: water, 10% bleach, hydrogen peroxide and Woolite® Oxyclean. The substrates were incubated for, two days, seven days, 42 days and 63 days before treatment with luminol or Bluestar Magnum® and subsequently sampled for DNA analysis. SETTING: Saint Louis Metropolitan Police Department Laboratory Division Forensic Biology/DNA Lab. SAMPLES: Blood was acquired from the Primary Investigator in EDTA tubes and from an expired blood unit donated by Saint Louis University Hospital. INTERVENTIONS: Blood was sampled onto six varying substrates at three different dilutions. Each stain was cleaned by one of four cleaning agents and allowed to stand for four pre-determined time durations. MAIN OUTCOME MEASURES: For each variable, chemiluminescence intensity was graded on a three point scale and mean values were compared for each latent bloodstain reagent. DNA results were also compared to a “blood control DNA profile” to determine if either reagent compromised DNA integrity. RESULTS: Bluestar Magnum® gave better chemiluminescence than luminol when detecting latent bloodstains. Neither reagent showed any degradation to DNA. CONCLUSION: Bluestar Magnum® has superior sensitivity and reactivity compared to luminol. Both reagents have comparable DNA results. Further studies with Bluestar Magnum® and cinderblock should be done. ABBREVIATIONS USED: DNA = Deoxyribonucleic Acid, EDTA = ethylenediaminetetraacetic acid, PCR = Polymerase Chain Reaction, PI = Primary Investigator