I got the citation for using silicone grease in phenol extractions: Mukhopadhyay, T. and J.A. Roth "Silicone lubricant enhances recovery of nucleic acids after phenol-chloroform extraction" Nucleic Acids Research. 21(3):781-182. 1993. The silicone grease I use is Beckman cat. no. 335148 I hope this helps. Daniel Kim