If It Is Blood Stain (Dried Blood) On A Piece Of Filter Paper, It Is Still OK To Use Our Blood & Tissue Genomic DNA Extraction Miniprep System To Extract DNA From It. What Dr. K. Nobuto Can Do Is To Cut The Filter Paper Into Small Pieces (About 10 Mm2). Place 1 To 4 Pieces (Depends On How Concentrated The Blood Stain Is) Into A Clean 1.5-Ml Eppendorf Tube. Add 20 Ml Proteinase K And 200 Ml LYS Buffer Into The Sample. Mix Immediately ByVortexing For 20 Seconds. Follow The Tissue Protocol From Step 3.