Hallo,

I recommend you the use of membranes. It is demonstrated that with cotton swabs you just take the very superficial, mostly airborne microorganisms, but not really those affecting the material. With membranes, you can cover more surface and the sampling is more accurate. There are different kind of membranes (nitrocellulose, polycarbonate and nylon). Please take a look at our publication: Piñar G, Tafer,H, Sterflinger K Pinzari K. Amid the possible causes of a very famous foxing: molecular and microscopic insight into Leonardo daVinci’s self-portrait. Environmental Microbiology Reports (2015) 7(6), 849–859, where we show results concerning this matter.

Regards,

Guadalupe

Hallo,

I recommend you the use of membranes. It is demonstrated that with cotton swabs you just take the very superficial, mostly airborne microorganisms, but not really those affecting the material. With membranes, you can cover more surface and the sampling is more accurate. There are different kind of membranes (nitrocellulose, polycarbonate and nylon). Please take a look at our publication: Piñar G, Tafer,H, Sterflinger K Pinzari K. Amid the possible causes of a very famous foxing: molecular and microscopic insight into Leonardo daVinci’s self-portrait. Environmental Microbiology Reports (2015) 7(6), 849–859, where we show results concerning this matter.

Regards,

Guadalupe

Thanks a lot Guadalupe. I have read several of your works. Regards

Dear Floris,

The use of membranes is not new, this sampling method was already described by Pitzurra et al.(1997a,b) and Poletti et al.(1999). The advantages of this sampling technique, especially for paper materials, over other minimal invasive or non-invasive sampling techniques (as sterile needles, adhesive tape and dry swabs) have been discussed carefully by other authors (see Cappitelli et al. Trends in Microbiology, December 2010, Vol. 18, No. 12). The use of needles and adhesive tapes may cause paper fragments to be removed, leading to severe surface damage; and dry swabs are non-invasive, but largely ineffective.

Membranes have more surface for sampling. The most used are the nitrocellulose membranes, 47 mm in diameter and 17.34 cm2, being pressed on the surface of the material for 20-30s, using swabs or fingertips protected by sterile gloves and immediately transferred to plates containing a specific growth medium. Particularly, I prefer the nylon membranes for doing molecular analyses. The nylon membranes can be directly used in combination with standard DNA extraction kits. This type of membrane is more convenient to handle because of its smaller size, which allows for its direct introduction into the commercial tubes supplied by some extraction kits, eliminating the need for additional prior procedures that could introduce greater risk of contamination. In this way we could really prove a more complex microbial community obtained when using membranes for sampling than when using swabs.

regards,

Guadalupe