FAQ

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

We recommend that Quality Biological SFM be supplemented with L-glutamine to a final concentration of 1-3 mM prior to use. Studies indicate that L-glutamine containing media, even when stored at +4° C, is stable for only 3 weeks. At higher temperatures, this particular amino acid is far less stable.

If our sera are stored properly, namely at -10 to -20° C, they should be acceptable for use up to 48 months. With the exception of DMEM, all other basal media stored at +4° C will have a 2-year expiration date. However, DMEM even at refrigerated temperatures, tends to precipitate after 1 year.

In general, water has an extremely low buffering capacity. It is not unusual for water to range in pH from 2 to 10 units.

Basically, there are two ways:
The “Weaning Method” and “The Quick Method.” These are described in the Quality Biological Catalog. In addition, a separate document describing these two methods and other aspects of serum-free cell culture is available. Click on Serum Free Medium Cell Culture to view or print the document.

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 requirement is 25L; whereas for products that can be autoclaved, our minimum is only 5L. Custom products can be packaged into 1mL to 20L size containers.

In general, water has an extremely low buffering capacity. It is not unusual for water to range in pH from 2 to 10 units.

SOC contains 20mM glucose whereas SOB has none

*Omitted from preparation. Add 20mM of MgCl₂ prior to use.

The difference between these two bacteriological media is their respective sodium chloride concentrations. Lennox L broth contains 5.0 g/L NaCl as opposed to Luria-Bertani which has 10.0 g/L of sodium chloride.

Regardless of whether our product is TE, pH 8.0 or TE, pH 7.4, the concentrations of Tris (T) and EDTA (E) are 10mM and 1mM respectively. Click on TIS to access the library of Technical Information Sheets for more information.

Our Prehybridization/Hybridization Buffer is qualified for DNA applications only (e.g. Southern Blotting). Click on TIS to access the library of Technical Information Sheets for more information.

For RNA applications (e.g. Northern Blotting), we recommend our Hybridization Buffer for Nylon Membranes. Click on TIS to access the library of Technical Information Sheets for more information.

Our DEPC (Diethyl pyrocarbonate) elimination process is proprietary. However, once we remove the DEPC from our DEPC-treated water, it is sterile filtered through 0.1 µm filter into 100 and 1L plastic (PET) bottles. Click on TIS to access the library of Technical Information Sheets for more information.

See the table below.

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)	–
EDTA	1 mM	–	–
Glycerol	50% (v/v)	30% (v/v)	20%
Tris base	–	–	100 mM, pH 6.8
SDS	–	–	4.0% (w/v)

Xylene cyanole (XC) and bromophenol blue (BPB) are tracking dyes for gel electrophoresis. According to either “Maniatis” (Sambrook, Fritsch & Maniatis (1989) Molecular Cloning, A laboratory Manual; 2nd Edition., CSHL Press) or FMC, the dyes migrate as follows:

i). Migration in a polyacrylamide gel:

ii). Migration in a denaturing polyacrylamide gel:

iii). Migration in an agarose gel (Source: FMC):

The formulation is provided in a Technical Information sheet available from Customer Service. Alternatively, it may be viewed on-line.

Click on TIS to access the library of Technical Information Sheets for more information.

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. Click on TIS to access the library of Technical Information Sheets for more information.

Our agar plates are supplied in two sizes: 15 X 100mm (standard) and 15 X 150mm. Our minimum 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.