Are your products environmentally friendly?

Yes. Quality Biological, Inc.,’s products and/or packaging contains recycled/renewable content, reduce waste, and are safer to human and environmental health.

Where can I find Certificates of Analysis, SDSs and product information?

All Certificates of Analysis can be found here with the product catalog number and lot number.

Product SDS and other information is available on the product’s page.

Cell Biology FAQs

CB-1. Should I supplement Quality Biological serum-free media (SFM) with L-glutamine prior to use? If so, what should be the final concentration of L-glutamine?

Quality Biological, Inc., Serum Free Media do not contain L-Glutamine and should be supplemented with L-glutamine to a final concentration suitable to your specific cell line. Most cell lines will require supplementing with L-Glutamine to a final concentration of 2-6 mM prior to use.

CB-2. How stable are your sera and basal media?

When stored properly at -10 to -20° C, sera can be used for up to 48 months. All our basal media stored at +4° C will have a 2-year shelf life from the time of manufacturing. However, DMEM is the only basal medium with a 1-year shelf life, the medium tends to precipitate after 12 months even if refrigerated.

CB-3. What is the pH of your Cell Culture Grade water?

Water has no buffering capacity. It is not unusual for water to range in pH from 2 to 10 units.

CB-4. How do I adapt my cells from a serum-containing medium to one of your serum-free media (SFM)?

There are two commonly implemented methods, “The Weaning or Step-Down Method” and “The Quick Method.” Description for these two methods can be found here.

CB-5. I am interested in your custom cell biology products. What are your minimum requirements for customized reagents?

We are committed to providing the very best custom manufacturing service and we are pleased to assist with both small and large volume requirements. If the product of interest must be sterile filtered, our minimum volume requirement is 25 Liters, whereas for products that can be autoclaved, our minimum volume is only 5 Liters. Custom products can be packaged into 1 mL to 20 Liters size containers.

Our Contract Manufacturing Information Request Form can be found here.

Our Custom Media Information Request Form can be found here.

CB-6. Why does trypsin turn yellow in color from the normal pink color? Is the product still good to use?

During shipping, the trypsin might change from pink to yellow in color due to exposure to carbon dioxide released from the dry ice in the shipping container. In our experience, this discoloration does not affect the functionality of the trypsin.

Molecular Biology FAQ‘s

MB-1. What is the pH of your DEPC-treated Water and Molecular Biology Grade Water?

Water has no buffering capacity. It is not unusual for water to range in pH from 2 to 10 units.

MB-2. What is the difference between your SOC and SOB media?

SOC medium is SOB medium supplemented with 20 mM glucose.

MB-3. What is the difference between your Lennox L and Luria-Bertani media?

The difference between these two bacteriological media is their respective sodium chloride concentrations. Lennox L broth contains 5.0 g/L NaCl and Luria-Bertani broth contains 10.0 g/L.

MB-4. What is the formulation of your TE buffers?

Regardless of whether our product is TE, pH 8.0 or TE, pH 7.4, the concentrations of Tris (T) and EDTA (E) are 10 mM and 1 mM respectively.

MB-5. Is your Prehybridization/Hybridization buffer qualified for RNA?

Our Prehybridization/Hybridization Buffer is qualified for DNA applications only (e.g. Southern Blotting). For RNA applications (e.g. Northern Blotting), we recommend our Hybridization Buffer for Nylon Membranes. Catalog #351-059-101.

MB-6. How do you remove DEPC from your DEPC-treated water?

Our DEPC (Diethyl pyrocarbonate) elimination process is proprietary.

MB-7. What are the compositions of your RNA, DNA, and SDS-Protein Gel Loading Solutions?

See the below table.


Components RNA Gel Loading Solutions, 10X DNA Gel Loading Solution, 5X SDS Protein Gel Loading Solution, 2X
Bromophenol Blue 0.25% (w/v) 0.25% (w/v) 0.2% (w/v)
Xylene cyanole 0.25% (w/v) 0.25% (w/v)
Glycerol 50% (v/v) 30% (v/v) 20%
Tris base 100 mM, pH 6.8
SDS 4.0% (w/v)

MB-8. Where do xylene cyanole (XC) and bromophenol blue (BPB) dyes migrate in agarose gel electrophoresis? Where do these two tracking dyes migrate in a polyacrylamide gel?

The dyes migrate as follows:

In 1% agarose TAE buffer, Xylene cyanole-4160 bp, bromophenol blue-370 bp

In 1% agarose TBE buffer, Xylene cyanole-3030 bp, bromophenol blue-220 bp

MB-9. What is the formulation of your RNA Gel Buffer (10X MOPS Buffer)?

MOPS 0.2 M, Sodium acetate-3H2O 0.08 M, Disodium EDTA-2H2O 0.01 M, pH adjusted to 7.0.

MB-10. Why do you not put formamide in your gel loading solutions?

Formamide, an organic denaturant, is commonly used in nucleic acid applications such as sequencing. It is well known that formamide, even at very low temperatures (e.g., –20 ° C), will break down into formic acid and ammonia. Both by-products are capable of degrading RNA and DNA. Thus, it is prudent to use freshly deionized formamide before adding it to our DNA Gel Loading Solution and/or to our RNA Gel Loading Solution.

MB-11. I understand that Quality Biological, Inc., can manufacture custom agar plates. What is your minimum number of plates for a custom order? What size plates do you use and what are their fill volumes? What is the turn-around time?

Our regular agar plates are supplied in two sizes: 15 X 100mm (standard) and 15 X 150mm but we can manufacture custom orders with other formats. Our minimum custom order requirement is 100 plates. You may specify a fill volume; we typically do 25 and 40mL fills. In most cases, we can deliver a custom order within 5-10 business days.

MB-12. What is the composition of your ACK lysing buffer?

ACK lysing buffer contains Ammonium Chloride (8.29 g/L), Potassium Bicarbonate (1.00 g/L) and EDTA (37.2 g/L).