PYREX® round bottom boiling flasks have short ring necks and take a No. 5 rubber stopper. These ring neck boiling flasks are precisely tooled for uniform stopper fit. These flasks are used in applications requiring rigid stoppering and as wash bottles in routine lab washing. They are manufactured from No. 7740 borosilicate glass. Wall thicknesses are carefully controlled to provide the proper balance between thermal expansion and mechanical strength for greater shock resistance. Their excellent chemical durability results in contamination-free results and long life under the toughest lab conditions. The normal working temperature for PYREX® boiling flasks is 230°C.

These test tubes are annealed, resistant to heat and chemically stable. Rims are fire-polished. The 25 mm diameter tubes do not have a marking spot.

These watch glasses possess high chemical durability, thus preventing contamination of solutions. They are molded to the same radius of curvature for convenient stacking. The heavy wall and ­uniform fire-polished edge provide mechanical strength. The outside diameter cannot be controlled within close limits and a slight degree of out-of-round can be expected to occur.

Bovine calf serum is a cost-effective alternative to Fetal Bovine Serum (FBS). It is often used with robust cell lines when large quantities of serum are needed such as in the manufacturing of biological drugs and vaccines. Bovine calf serum is derived from calves that are generally less than 22 weeks old. It has very high levels of transferrin, which allows for iron fortification to levels of more than three times greater than normal FBS. Iron is essential for cell respiration and metabolism and for some cell lines, makes up for the lower levels of growth factors and other metabolites found in calf serum when compared to FBS.