Support & Resources


Drop-n-Stain™ Secondary Antibodies: fast & easy, no pipetting

Drop-n-Stain™ Secondary Antibodies are provided in a convenient dropper bottle for easy dispensing without pipetting. Drop-n-Stain™ secondaries feature affinity-purified, highly cross-adsorbed secondary antibodies conjugated to Biotium’s CF® dyes. CF® dyes are superior to Alexa Fluor®, DyLight®, and Cy® dyes for antibody labeling by having combined advantages in brightness, photostability, and specificity.

Drop-n-Stain™ secondaries come in four reactivities:

Drop-n-Stain™ secondaries are offered in four fluorescent dye conjugates:

  • CF®488A is a superior alternative to the traditional green fluorescent dye FITC (or fluorescein) owing to its exceptional brightness and photostability. CF®488A has brightness and photostability comparable to Alexa Fluor® 488.
  • CF®543 is an orange fluorescent dye with an excitation spectrum optimally matching the 543 laser line. Antibody conjugates of the dye are much brighter than those of Alexa Fluor® 546.
  • CF®594 is spectrally similar to Alexa Fluor® 594 and Texas Red® dye but yields much brighter protein conjugates due to its high quantum yield and exceptional water solubility. CF®594 also has excellent photostability ideal for demanding applications, such as confocal microscopy and single molecule imaging.
  • CF®640R is a novel rhodamine-based dye spectrally very similar to Cy®5 and Alexa Fluor® 647. CF®640R is much brighter than Cy®5 and at least as bright as Alexa Fluor® 647 when excited at 633 or 635 nm. However, the most important advantage of CF®640R is its exceptional photostability. CF®640R is far more photostable than the cyanine-based dyes Cy®5, Alexa Fluor® 647 and Atto 647N.