Siliconized Plasticware

The use of siliconized plasticware helps prevent loss of pseudovirions due to non-specific interactions with polypropylene during storage. Unfortunately, siliconized sterile screw-cap siliconized tubes are a pain in the neck to obtain.  A company called BioPlas is the only source we have run across for such tubes.  Flip-cap siliconized tubes are widely available from various sources, but flip-cap tubes are more difficult to keep sterile.

BioPlas seems to carry very little inventory and it can take weeks to months to receive the tubes.  BioPlas also declines to take credit cards, so we have to order the tubes through Fisher or VWR.

We’ve previously observed loss of L1 over the course of a couple weeks’ storage at 4ºC when Optiprep fractions were stored in PGC brand “low adhesion” flip cap tubes.  We infer that “low adhesion” plastic may not be substitutable for “siliconized” plastic. Adding 10% serum to Optiprep fractions helps prevent titer losses during extended storage at 4ºC.  Detergents may also help prevent titer loss (see Shi (2005) J Pharm Sci 94:1538).

ESP Chemicalsis one possible source of BioPlas brand tubes.

Siliconized pipet tips:   

Since pseudovirions spend very little time in contact with pipet tips, the use of siliconized tips is not essential.