Store › SiR-tubulin kit 50 nmol Image 1 of 1 SiR-tubulin kit 50 nmol $1,184.00 Quantity: Add To Cart Added! SiR-tubulin is a fluorogenic, cell permeable and highly specific probe for microtubules. SiR-tubulin is a fluorogenic, cell permeable and highly specific probe for microtubules.