PMC

SXT entrance filter frame. The filter membrane itself has been destroyed in testing, showing the catastrophic degradation typical of the failure of thin films of this type.

Cells and slides were prepared as described under “Materials and Methods.” Images in frames A–N, R, and S were made using a GFP filter set. Frames O–Q demonstrate co-localization of GFP fluorescence (frame P) and DAPI-positive staining (frame O). In Frame Q, DAPI-positive staining was pseudo-colored red. The image containing the pseudo-colored material was then superimposed on the image in frame P. The two images in frame Q were aligned using only the margins of the cells, not the DAPI- or GFP-positive regions.

Structural interpretation of mucolipidosis type IV pathogenesis. Mapping of human mucolipidosis type IV mutations onto the structure of an mTRPML1 subunit. Note that PMD and pore filter region are mutation hot-spots. Blue ball indicates missense mutation, red balls indicate mutations causing amino acid premature stop codon (X) and yellow ball indicates in frame deletion (Δ). See also Figs. S2, S4, and S5

Cage types and sampling methods. (A) Type II open polycarbonate cage (floor area, 344 cm²; height, 13.5 cm) with wire lid holding chow and water bottle. (B) Same cage setup as in panel A but with an additional soft filter top composed of a flexible polyethylene frame holding a polypropylene filter. The water bottle is positioned halfway across the cage, through a cross cut in the paper filter of the filter top. (C) Same cage setup as in panel A but with an additional rigid filter top composed of a rigid polycarbonate frame holding a polyester filter (static microisolation caging). (D) Same cage set up as in panel A but covered with a nonsealed, solid stainless-steel lid and used in an IVC rack as described. The cages shown in panels A through D had no seal between cages and lids. (E) Type II long, sealed, polyphenylsulfone cage (floor area, 501cm²; height, 13.5 cm) with polyphenylsulfone lid holding a polytetrafluorethylene membrane filter and used in an IVC rack. Silicone gaskets were placed between cages and lids. (F) Stationary air pump and sampling head carrying a filter for the collection of ambient samples. (G) Portable air pump with sampling head attached to a staff member for the collection of samples fom the breathing zone at the upper chest level during cage changing on a stainless steel table. (H) Electrostatic dust fall collectors (EDC) for the collection of ambient samples. (I) EDC (arrow) positioned on top of an IVC rack. (J) 2 EDC positioned on a sampling table in the wash room.