What is rTrysin?  
Recombinant Trypsin (rTrypsin) is an animal origin-free alternative to animal-derived Trypsin. rTrypsin hydrolyzes peptide bonds where the carboxyl part of the peptide bond is contributed by either Lysine (Lys) or Arginine (Arg).  
  
Does Novozyme provide rTrypsin in a solution format?  
No, rTrypsin is only available as a solid product (granulate).  
  
In what unit size does Novozymes sell rTrypsin? 
We offer rTrypsin in pack sizes of 100g and 1 kg.  

Sampling
How can I get a sample of rTrypsin? 
You can obtain a sample of rTrypsin by clicking the contact us link at the top of this page. 

Handling and formulation  
How should I store rTrypsin?  
Recommended storage is 0-25°C (32-77°F). Packaging must be kept intact, dry and away from sunlight. The product performs optimally when stored as recommended and used prior to the best before date. When you have formulated the rTrypsin granulate to a liquid form we recommend that you freeze the liquid at the required end concentration and divide your solution into small aliquots in order to avoid future freeze and thaw.  
  
Which buffer is required for dissolving rTrypsin? 
We recommend using a PBS buffer adjusted to pH 7. Depending on the cell line, the suggested rTrypsin concentration should be adjusted to 0.2 mg/ml (corresponding to 200 U/ml rTrypsin with an activity of 1000 USP/mg) and sterile filtered. For some cell lines EDTA needs to be added. The addition of EDTA usually accelerates the dissociation phase. 
Incubating cells with too high a trypsin concentration for too long a time period will damage cell membranes and kill the cells. If unsure about the concentration of trypsin to use, use a low concentration (0.02% - 0.05%).  
  
Is there EDTA in rTrypsin?  
rTrypsin contains enzyme concentrate, sodium chloride and around 1% water. There is no EDTA in the product. The product is free from undesirable proteases such as carboxypeptidase and chymotrypsin.  
Which concentration of EDTA I can add for good detachment?  
It depends on the cell line but we recommend 0.5 – 1 mM EDTA.  
  
Specifications
What is the activity unit of Novozymes recombinant trypsin?  
The unit activity is USP/mg and the lower limit is 800 USP/mg.  
  
I am not familiar with USP unit calculation; how does it correspond to the BAEE Unit?  
The USP units are determined as follows:  
  
USP Unit
Adheres to the Schwert & Takenaka method* but activities are 1/3 of the S & T-units (BAEE Units). 
1 USP-unit catalyzes a change in adsorbance at 253 nm of 0.003 per minute at 25°, pH 7.6 using N-benzoyl-L-arginine ethyl ester (BAEE) as substrate.  
*Schwert & Takenaka devised an assay method for tryptic activity using N-α-benzoyl-L-arginine ethyl ester (BAEE) as substrate. 1 S & T-unit catalyzes a change in absorbance at 253 nm of 0.001 per minute at 25 °, pH 7.6 in a reaction volume of 3.2 ml. 
1 USP Unit is approximately equivalent to 3.0 BAEE Units. 
  
Customer technical support 
Gamma irradiation is typically performed on animal origin trypsin to ensure inactivation of any animal origin viruses. Is it necessary to perform gamma irradiation on rTrypsin?  
rTrypsin is manufactured by an animal origin-free process so it is not necessary to perform gamma irradiation on rTrypsin.  
  
What is the PI (Isoelectric point) of rTrypsin? 
The theoretical PI is 8.52 but our laboratory has measured the PI at 9.5 (a slight difference from the theoretical PI).  
  
What is the cleavage specificity compared to porcine trypsin? 
Our scientists have compared the cleavage specificity of rTrypsin to porcine trypsin and found the cleavage specificity of rTrypsin to be very similar. Both trypsin products cleave after R (Arginine) and K (Lysine).  
  
Regulatory affairs 
According to which standards is rTrypsin produced? 
rTrypsin is a technical product manufactured under ISO standards. It is not produced under GMP and is not pharmaceutical grade.