Porous planar cell capture system
The invention relates to a porous planar cell capture system for use in determining the presence and/or amount of cells, for example, viable cells, in a liquid sample, and to methods of using such a cell capture system. The cell capture system contains a fluid permeable, planar membrane adopted to retain cells thereon, a fluid permeable support member that supports the membrane, and an optional register associated with the membrane.
1. A cell capture system comprising:
(a) a fluid permeable, planar membrane comprising an exposed first surface and a second opposing surface, at least a portion of the first surface is adapted to retain cells thereon, the portion:
(i) defining a plurality of pores having an average diameter less than about 1 μm so as to permit fluid to traverse the portion of the membrane while retaining cells thereon;
(ii) being substantially non-autofluorescent when exposed to light having a wavelength in a range from about 350 nm to about 1000 nm; and
(iii) having a flatness tolerance of up to about 100 μm when a fluid sample has passed through the membrane;
(b) a fluid permeable support member adjacent and supporting at least a portion of the second opposing surface of the membrane, the fluid permeable support member comprising an upper surface that contacts the second opposing surface of the membrane and has a flatness tolerance of up to about 100 μm so as to maintain the flatness tolerance of the portion of the membrane when the fluid sample has passed through the membrane; and
(c) an optional register associated with the membrane.
2. The system of claim 1 , wherein the membrane comprises a disc.
3. The system of claim 2 , wherein the disc has a thickness in a range selected from the group consisting of: from 1 μm to 3,000 μm; from 10 μm to 2,000 μm; and from 100 μm to 1,000 μm.
4. The system of claim 1 , wherein the support member has a thickness in a range selected from the group consisting of: from 0.1 mm to 10 mm; from 0.5 mm to 5 mm; and from 1 mm to 3 mm.
5. The system of claim 1 , further comprising a mask proximate at least another portion of the first surface of the membrane.
6. The system of claim 5 , wherein the mask is circular.
7. The system of claim 1 , further comprising a plurality of detectable particles.
8. The system of claim 7 , wherein the particles are fluorescent particles.
9. The system of claim 8 , wherein the particles are adapted to be excited by light having a wavelength at least in a range from about 350 nm to about 1000 nm.
10. The system of claim 9 , wherein the particles are adapted to be excited by light having a wavelength at least in one range from about 350 nm to about 600 nm and from about 600 nm to about 750 nm.
11. The system claim 1 having a sterility assurance level less than 10 −6 , 10 −7 , 10 −8 , or 10 −9 .
12. A cell capture system comprising:
(a) a fluid permeable, planar membrane comprising an exposed first surface and a second opposing surface, at least a portion of the first surface is adapted to retain cells thereon, the portion:
(i) defining a plurality of pores having an average diameter less than about 1 μm so as to permit fluid to traverse the portion of the membrane while retaining cells thereon;
(ii) being substantially non-autofluorescent when exposed to light having a wavelength in a range from about 350 nm to about 1000 nm; and
(iii) having a flatness tolerance of up to about 100 μm when a fluid sample has passed through the membrane;
(b) a fluid permeable support member adjacent and supporting at least a portion of the second opposing surface of the membrane, the fluid permeable support member comprising an upper surface that contacts the second opposing surface of the membrane and has a flatness tolerance of up to about 100 μm so as to maintain the flatness tolerance of the portion of the membrane when the fluid sample has passed through the membrane;
(c) an optional register associated with the membrane; and
(d) a mask comprising a plurality of detectable particles disposed within a well defined by the mask.