Table 1.

Assay Materials

Name of Reagent	Source	Catalogue Number	Comments
Calcein AM (CaAM)	Anaspec, Fremont, CA	89203	Supplied as 5 mM in 200 μl DMSO. Store desiccated, protected from light, at -20°C. For source stock of 2 mM, add 300 μl DMSO, and store aliquots as above, under argon (Ar).
Dimethyl sulfoxide (DMSO)	Sigma-Aldrich, Saint Louis, MO	D2650	Transfer contents of one ampoule to polypropylene snap-cap tube. Purge with Ar gas, desiccate, protect from light, store at room temperature (rt).
SYTOX® Orange (SO)	Molecular Probes, Eugene, OR	S-11368	Supplied as 5 μM in 250 μl DMSO. Store desiccated, under Ar, protected from light, at -20°C. Harmful.
Water, sterile, cell culture grade	Sigma-Aldrich	W3500	May use equivalent.
Poly-L-Ornithine (PORN)	Sigma-Aldrich	P4957	Supplied as 0.01% (w/v) solution in water. Store refrigerated.
Sodium hydroxide	Sigma-Aldrich	S2770	Sterile 1 N solution. Store at rt. Corrosive.
Hydrochloric acid	Sigma-Aldrich	H9892	Sterile 1 N solution. Store at rt. Corrosive.
Probenecid	Sigma-Aldrich	P8761	Store solid desiccated at rt; initial stock of 45.7 mg/ml made up in 1 N NaOH and stored refrigerated (not more than 1 mo) until use.
Staurosporine (Stsp)	EMD Millipore, Billerica, MA	569396	Supplied as 1 mM solution in DMSO. Equivalent may be obtained from various sources. Store desiccated, protected from light, at -20°C. Toxic.
Cumene hydroperoxide (CuOOH)	Sigma-Aldrich	24,750-2	Supplied as approximately 80% purity in water. Store refrigerated, tightly capped, protected from light, with air space gassed with Ar. Toxic.
Saponin	Sigma-Aldrich	S4521	Store solid at rt. Make 0.1% (w/v) solution in MEBSS based on total weight of solid supplied, not sapogenin content.