Enzyme Research Laboratories, Inc. makes the following suggestions for the storage and handling of purified proteins:
- Most purified proteins are stable at low temperatures and should be stored at <-60°C.
- Lyophilized proteins should be reconstituted using a good laboratory quality H2O. After reconstitution the protein should be aliquoted into a useful (one time use) size and stored at <-60°C.
- Freeze proteins in a concentrated form and as soon as possible. When dilution is necessary, dilute immediately prior to use. When possible, dilution buffers should contain stabilizers such as albumin.
- Limit thawing and refreezing. Multiple thaw/freezes can reduce
protein activity and cause degradation. We always suggest aliquoting the protein into a single use size.
- Refrigerate thawed proteins or store on ice. Proteins warmed even to room
temperature may degrade quickly.
- One exception to # 5 is Fibrinogen. After thawing Fibrinogen, keep at room temperature. Fibrinogen will come out of solution if it is cooled
- Products provided in Glycerol/buffer solutions should be stored at -20°C. Temperatures below -30°C can cause phase transitions and need to be avoided.
- 1 PEU is equal to the amount of activity found in one mL of plasma as determined in factor deficient clotting assay.
- All extinction coefficients are reported for 280 nm using 1 cm path length.
Antibody Use (general recommendations)
The optimal concentration of antibody for any particular application will vary depending on the antibody format as well as the detection method used. We strongly suggest each antibody be titrated by the end user to determine the optimal working concentration for each particular application. The following chart contains general recommendations only and may not apply to all products.
|Format||Immunoblotting (ECL detection)||ELISA (capture)||ELISA (detecting)|
|Whole IgG (IG)||5-25 ug/mL||20-50 ug/mL||NA|
|Affinity-Purified (AP-IgG)||0.5-5 ug/mL||10 ug/mL||NA|
|IgG Peroxidase (HRP)||5 ug/mL||NA||10 ug/mL|
|AP-IgG Peroxidase (AP-HRP)||1 ug/mL||NA||2 ug/mL|
Unless otherwise noted, all the coagulation factors are stored at <-60°C and shipped on dry ice by overnight carrier. Shipping will be billed.
All Human Source material is tested and found negative for all communicable diseases, including HIV-1 and HIV-2 antibodies, HCV, Rapid Plasma Reagin and Hepatitis B Surface Antigen. Because no test method can offer complete assurance that Human Immunodeficiency Virus (HIV), Hepatitis B virus or other infectious agents are absent, all human proteins should be handled as suggested in the U.S. Department of Health and Human Services Manual on Biosafety in Microbiological & Biomedical Laboratories.