Packaging and storage— Store platelets in an approved container.Platelets may be stored in plasma or in an approved additive solution at 20to 24with continuous gentle agitation for no more than 5days after date of preparation.

Labeling— Label the container to indicate the collection date,the donation number or other coding means to uniquely identify the unit and to provide traceability to the donor,approximate volume,storage temperature,and its expiration date.Indicate the anticoagulant solution used and any additive solutions added subsequent to collection.Also label the container to identify donor status (for example,volunteer or paid).Label it also with the following statements:“See Circular of Information for the Use of Human Blood and Blood Components for indications,contraindications,cautions,and methods of infusion”;“Properly identify intended recipient”;“This product may transmit infectious agents”;and “Rx only.”In addition,label the container to indicate the product name as indicated in Table 1.[NOTE—The name is determined by the method of platelets preparation (derived from whole blood or by apheresis)and by performing the necessary testing to ensure that the product meets the minimum requirements for the named products,as indicated in Table 1.] [NOTE—Platelets prepared by apheresis should be labeled with the donor's ABOblood group and Rh factors.Test the donor's whole blood or red blood cells as directed under Whole Bloodor Red Blood Cells,respectively.]

Identification— Dilute a small volume of Platelets 1:1000with 0.9%sodium chloride solution.Place a small drop of the diluted platelets onto the end of a clean glass microscope slide.Obtain a second clean glass microscope slide,and draw its edge across the drop of platelets so that capillary action spreads the drop across the first slide.Push the second slide in one smooth motion across the first slide to make a smear of platelets.Allow the smear to dry.Apply a liberal amount (1to 2mL)of Wright's stain to the platelet smear,and allow to stand for 2minutes.Dip the slide in deionized water,and gently blot dry with absorbent paper.Examine the slide using a microscope at 100×with bright illumination.Platelets appear as anuclear round or oval shapes approximately 0.1to 0.2µm in diameter,with some fine purple granulation.The platelets may occasionally appear to have a purple center with clear cytoplasm at the periphery.

Platelet count— Use a commercially available,validated hematology analyzer to determine platelet count.Proceed as directed in the instrument's operating manual.

Residual leukocyte count— Place 100µLof Platelets into a suitable test tube.Add 400µLof 0.01%(w/v)crystal violet in 15%(v/v)acetic acid,and mix thoroughly.Fit a hemocytometer with a 50-µLcounting volume and a bright background with a cover slip.Load the counting chamber with the mixture until the counting area is completely covered,but do not overfill.Cover the counting chamber with a suitable moist lid to prevent evaporation,and allow to settle undisturbed for 10to 15minutes.Remove the lid,and place the chamber on the stage of a light microscope fitted with a 10×ocular lens and 20×objective.Count the leukocytes in the entire 50-µLcounting volume.Calculate the leukocyte count in the platelets,expressed in leukocytes per µL,by dividing the observed leukocyte count by 10.Calculate the total number of leukocytes in the red blood cell unit as follows:

pHá791ñ(for stored Platelets)— Transfer aseptically a volume appropriate for the equipment:pHmust be greater than 6.2throughout the storage period.USP28

Expert Committee:(BBP)Blood and Blood Products

USP28–NF23Page 278

Phone Number:1-301-816-8339