ADC and ODC Related Questions
CellMosaic provides antibody drug conjugate (ADC) and other drug conjugate (ODC) related products and services. The following lists some of the frequently asked questions regarding the general applications and usages of these products. For specific product questions, please click here. For service-related questions, please click here.
How many antibodies can I label with CellMosaic’s ADC kit?
CellMosaic’s ADC kit is configured by the number of labeling reactions, not the number of antibodies. In the “Number of Reactions” on each kit's product page on the website, if you choose 1, you will get the price and catalog number for a one reaction kit (x1). If you choose 3, you will get the price and catalog number for a three reaction kit (x3). The three reaction kit is usually around 20% cheaper than the one reaction kit.
What is the difference between ordering one three reaction kit (x3) or three one reaction kit (x1)?
The three one reaction kits are good if you want to conduct three (3) labeling reactions at different time points. The three reaction kit is around 20% cheaper than the one reaction kit and is good if you want to conduct three (3) labeling reactions simultaneously or within a short time frame as the buffers are packaged in the same tube for all three reactions.
I have only a small amount of antibody, can I split the reagents for multiple labeling?
Unfortunately, no. The ADC kit only comes with one or three sets of purification and buffer sets. If you split the reagents, you would not be able to complete the conjugation and purification.
Does CellMosaic sell protein-drug conjugation kits that work with single-domain antibodies (~15KDa)?
Yes, we currently have four PerKit™ products that can be modified to accommodate a 10-20 KDa antibody: Protein Mertansine (DM1) Conjugation Kit (CM11414), Protein MMAE Conjugation Kit (CM11413), Protein Deruxtecan Conjugation Kit (CM11432), and Protein SN38 Conjugation Kit (CM11430). If the kit you would like to modify is not listed above, please contact us to see if we can find you a custom solution.
How do I properly dispose of the hazardous waste from my ADC or PDC conjugation kit?
The best way to dispose of hazardous waste from using our kits is to put used columns and emptied tubes of reagents in the plastic waste bag provided and close it. Dispose of the entire waste bag as solid lab waste according to local regulations. We do not recommend treating hazardous waste without consulting your EHS specialists.
I am worried about the solubility of our antibodies - Can I substitute PBS for the buffers included in my ADC conjugation kit?
Unfortunately, you cannot substitute PBS for the buffers in our kits. The buffer systems we have designed for the kits are key to the success of your conjugation. The buffer systems have been extensively tested and used by our customers. We have not seen any precipitation or solubility issues caused by these buffers. However, if you have an antibody with properties that are quite different from a conventional antibody and are concerned with the solubility, you can contact us for suggestions.
What can I do to reduce aggregation of my ADC?
Aggregation is generally caused by the loading or stacking of hydrophobic drugs on your ADC. CellMosaic’s ADC kits use clinically approved conventional linkers, such as VC-PAB, ethylene type for proof-of-concept studies. These conventional linkers add hydrophobicity to ADC and aggregate the problem. To reduce the aggregation in ADC, you can use a more water-soluble drug or load the drug with a less hydrophobic linker such as our super hydrophilic AqueaTether®(AqT®) linker. If you do not want to change the configuration of your ADC, you can try to decrease the number of drugs loaded per antibody. For long-term storage of your ADC, we recommend using our ADC Stabilizing Buffer, which helps to keep the aggregation low during storage.
Which kit should I use to conjugate a ~50 KDa protein?
You can use any of the protein-drug conjugation kits. We currently offer protein-drug conjugation kits for DM1, SN38, MMAE, Deruxtecan, and other small molecules containing one carboxylic acid group. Additional kit configurations can be added depending on customer request. Please inquire if you do not see the drugs listed or to request a custom conjugation service.
Note: With a smaller protein/antibody, the amount of drug you can load without too much aggregation is limited.For further information on this topic, see ‘What can I do to reduce aggregation of my ADC?’
Can CellMosaic’s antibody-drug conjugation kits be used to conjugate nanobodies instead of antibodies?
No, CellMosaic’s kits that include “antibody” in the name are specifically designed for use with IgG1 type antibodies with a MW of ~150 KDa. However, CellMosaic has protein-drug conjugation kits that may be used for nanobodies depending on the MW. If your nanobody has a MW of ≤20 KDa, you may need some customization of these kits or to request custom conjugation services. We can also provide a custom conjugation service in which we make an initial batch of your nanobody-drug conjugate and use that synthesis process to design a kit for you for future use.
What concentration should I use for ADC controls (i.e., CM51100, CM51101, CM51102, CM11429) in my model?
As a general rule for any control, you should use the same drug concentration as your binding ADC (taking into consideration the DAR). The concentration of binding ADC you use will depend on your application. For cell viability studies to determine the IC50, you can use various concentrations ranging from 0.001 µg/mL to 10 µg/mL. These non-binding ADC controls can also cause some non-specific cell death. Keep this in mind when choosing your control.
In addition, if you need a negative control for linker only, you can conjugate your antibody with a VC-PAB linker without toxin. A different control option can be made using our control kit CM11429, which prepares a binding antibody without the toxin.
For ADC concentration measurements, is it okay to use Nanodrop?
Usually, the traditional UV method using a UV cuvette (1 cm path length) is good for measurements. Some of our customers do use Nanodrop for measurements, but we have not tested how accurate it is. You may need to do two measurements by zeroing it separately at 248 and 280 nm.
Do you have an ADC kit for antibody conjugation with Mc-VC-PAB-SN38?
We currently do not have a kit for Mc-VC-PABC-SN38. SN38 is extremely hydrophobic. We will not be able to use VC-PAB linker directly for this molecule. However, we do have our proprietary superhydrophilic AqT® linker that can be used with VC-PAB-SN38 to dramatically increase the water solubility. You can find more information by checking AqT® ADC development and manufacturing. We also have an antibody Deruxtecan conjugation kit (Cat# CM11431) that you can purchase on our website. Deruxtecan has a similar structure as SN38 with a cleavable peptide linker.