Do Membrane Filters prevent Cell Contacts?

Abstract

MEMBRANE filters have been used by experimental embryologists and immunologists to separate tissue components and cell populations in experiments designed to distinguish between cell mediated communicative systems and soluble messengers. Most commonly, ‘Millipore’ filters have been used both in the construction of diffusion chambers¹ and in in vitro studies with isolated and recombined tissue components². Few systematic studies have been made into the completeness of separation and on the correlation between filter thickness and pore size with cytoplasmic ingrowth. Grobstein and Dalton³ have reported that ‘Millipore’ filters with an average pore size of 0.1 µm prevented virtually all cytoplasmic ingrowth. Most experimentalists have used ‘Millipore’ filters with even larger pores (0.45 µm to 0.8 µm) in the belief that they prevent cell contacts (see ref. 4).