Secondary Antibody Product Listings

Biotium ships all antibodies (primary, secondary and conjugates) at room temperature. We guarantee their quality and performance under these conditions based upon our stability testing. Antibodies were subjected to accelerated stability testing by storing them at various temperatures (4°C, room temperature, or 37°C) for 1 week to mimic simulated shipping conditions and tested in immunostaining experiments. All antibodies showed the expected brightness and specificity, even after storage at sub-optimal temperatures for a week or longer. You can also download our Product Storage Statement here.

In line with our goal to be more environmentally friendly by reducing the use of excess packaging, and lowering shipping costs for our customers, products that have passed our stability testing are shipped at room temperature.

Once you have received the antibody vial, please follow the long-term storage instructions on the product information (PI) sheet.

Some of our products are packaged from a solution followed by solvent evaporation or lyophilization. If the chemical compound is very lightly colored or colorless and in small quantity, it may become thinly coated on the wall of the vial, making the vial appear empty. So, before you ask for a replacement, please inspect the vial carefully.

To dissolve lyophilized compounds, simply add the appropriate volume of the recommended solvent to the vial to make the desired concentration stock solution, and swirl or gently vortex to mix. Make sure the solvent comes in contact with the inside walls of the vial to fully recover the product.

Note that blue fluorescent dyes such as CF^TM350, CF^TM405M, and CF^TM405S are colorless or very pale yellow, and may be difficult to see.

There are usually three aspects to dye stability: 1) chemical stability of the dye core structure; 2) stability of the reactive group; and 3) photostability of the dye.

Chemical stability of the dye core structure:

This refers to resistance of the dye core structure to decomposition caused by factors other than photo-bleaching. These factors may include temperature, pH and incompatibility with other chemicals in the medium. This type of stability information is most useful for estimating the shelf-life of the dye that is already covalently attached to another molecule (e.g., an antibody), or for assessing the chemical compatibility of the dye in certain applications. CF® Dyes bear the core structures of coumarin, pyrene, rhodamine or cyanine dyes, all of which are known to have excellent chemical stability. In general, CF® Dyes are far more stable than the antibodies they label. Thus, if a CF®-labeled antibody loses activity during storage, the problem is not likely to be caused by the dye. CF® Dyes are also stable enough for labeled nucleic acids to be used in PCR or nucleic acid hybridization, where high temperature is involved.

Stability of the reactive group:

Reactive CF® Dyes comprise a reactive group used in bioconjugation. Among the various reactive groups, only amine-reactive succinimidyl ester (SE) and thiol-reactive maleimide groups are unstable because the small amount of moisture trapped in or leaked into the packaging vials can cause hydrolysis of the reactive groups over time. The SE group, in particular, is susceptible to degradation. Thus, in order to slow degradation, CF® Dyes comprising these reactive groups must be stored at -20°C under anhydrous conditions. Furthermore, stock solutions of the dyes must be made using dry solvents, such as anhydrous DMSO. One advantage of CF® Dye SE products over other commercial dyes is their relatively high stability. Normally, an SE group can be derived from either an aliphatic or an aromatic carboxylic acid group, but an aliphatic carboxylic group tends to result in a more stable SE, offering higher resistance to hydrolysis and thus better labeling efficiency. All of the CF® SE Dyes have their SE groups derived from aliphatic carboxylic acid groups, unlike many commercially available SE dyes that are often prepared from aromatic carboxylic acid groups.

Photostability:

This refers to the dye’s ability to withstand photobleaching. For most dyes, photostability is not a major problem for routine handling under ambient light or for applications, such as flow cytometry and Western blotting, where the dyes are only briefly exposed to light. However, for microscopy, especially for confocal microscopy, where the dyes may be subject to intense illumination for an extended period of time, photobleaching can be a major concern. Similar to the photostability of other fluorescent dyes, both the dye core structure and the structure-modifying groups attached to it play a role in the photostability of CF® Dyes. CF® Dyes bear the core structure of rhodamine, cyanine, pyrene or coumarin dyes; among the four types of core structures, rhodamine core is the most photostable, followed by cyanine and then by pyrene and coumarin cores. The structure-modifying groups and the way they are attached to the dye cores are a key innovative aspect of CF® Dye technologies that contributes to the superior photostability of CF® Dyes over that of other commercial dyes. In general, rhodamine-based CF® Dyes, whose wavelengths range from visible to the near-IR region, offer the best photostability, making the dye ideal for microscopy applications.