Specimen Collection

We rely on quality specimens from our clients to provide accurate results. Correct preparation, collection, and shipping methods are essential. Please refer to the test list for specific requirements; however, some general information is below.

Labeling of Specimens

Proper Labeling

Specimens submitted for analysis must be properly labeled with the patient's/employee's full name, patient ID, date and time of collection and specimen type if not obvious.

Storage and Shipping

Please follow analyte-specific instructions for storage and shipment of specimens.


Specimens must be submitted along with a requisition that contains the patient/employee name, age, sex, date drawn, test(s) requested, and pertinent billing information (please refer to the "Billing Policies" section). Please keep the back copy of the requisition for your office records. Customized multiple patient/employee requisitions are available upon request.

Biological Monitoring: Collection Tubes

Serum for PCB, pesticide and herbicide analysis should optimally be collected in plain red top tubes (without separator gel) and transported in plastic vials or glass tubes with teflon-lined caps. Lavender top tubes collected for whole blood analysis of volatile compounds should be completely filled and kept under refrigeration. Partially filled tubes may compromise results. Under no circumstances should any specimen for analysis of a volatile compound be opened or transferred to another tube prior to shipping.

Biological Monitoring: Collection Times

Specimens for many biological monitoring analytes are best obtained at a specified time; please refer to individual test requirements or to the Biological Exposure Index (BEl) section.


Refrigeration is adequate for storage of most specimens, but occasionally freezing or special preservatives are needed; see individual specimen requirements

Specimen Types

Whole Blood

Sent through our website, or email, printer, fax, mail, modem to modem, and/or computer disk depending upon the specific needs of the client. STAT testing is available for some procedures and same day testing is available for most procedures. Additional charges may apply for STAT services (please call Client Services). Telephoned and special reporting methods are available upon request.


Draw sufficient amount of blood with recommended anticoagulant to yield required plasma volume. Immediately after collection gently mix by inverting tube 5 times. Centrifuge at maximum speed for 10 minutes. Remove stopper and pipette plasma to a labeled plastic vial. Be sure to label the vial "plasma". Refrigerate.


Draw sufficient blood in plain red top tubes (preferred for most biological monitoring) or serum separatortubes (SST) to yield required serum volume (see specimen requirements for the analysis being ordered). Leave stopper intact throughout collection and centrifugation. Perform venipuncture and if using SST tubes invert the tube gently five times as specified in the manufactures instructions; further inversion may alter specimen integrity. Allow blood to clot at room temperature for a minimum of 30, but not longer than 60 minutes (leaving the serum on the clot for more than 60 minutes may alter test results). Centrifuge at maximum speed (2200 to 2500 rpm) for 15 minutes. Remove stopper avoiding serum contamination with red cells. CarefuIly pipette (plain red top tube) or pour (SST tube) serum into a labeled serum transport vial. Do not send SST tubes to the laboratory. The tubes must be spun within sixty minutes of collection and the serum poured off into a plastic serum transport tube. Refrigerate, unless otherwise specified.

Random Urine

Please follow specific specimen requirements for the analysis requested. Specimens for most analyses may be collected and transported in plastic screw-capped vials, but some may require special handling and/or preservatives. In addition, you may wish to refer to the "Biological Exposure Indices (BEI) Testing" section of this Directory of Services for recommended times of collection. Specimensfor urinalysis and/or urine culture and sensitivity must be collected by the clean-catch midstream method using the sterile containers provided by the laboratory. Urine should then be transferred according to instructions to special gray-stoppered urine transport tubes which contain a preservative to prevent further growth of bacteria. The first urine voided in the morning is the recommended and preferred specimen; please indicate the date and time of collection on the test requisition form and the container label.

Blood Collection Tubes

Serum Separator Tube (SST)

Contains a gel which when centrifuged forms a barrier to separate the blood cells (clot) and the serum. Used to collect serum for most routine medical surveillance testing. For the most accurate test results, it is best if serum is not transported in this tube, but poured-off and transported in a plastic vial.

Red Top Tube

Contains no anticoagulant or preservative. Used for serum samples in which contact with serum separator gel tie. SST) may cause interference with the analysis tie. serum PCB and pesticide and herbicide measurements, as well as, serum to be archived). For Therapeutic Drug Monitoring tests your tube of choice for original specimen collection container will be a Red Top Tube. Then transfer collected specimen to a serum transport vial.

Royal Blue Tube Top

Contains EDTA and used for whole blood analysis of trace metals.

Gray Tube Top

Contains sodium fluoride as preservative and potassium oxalate as anticoagulant; used for both whole blood and plasma analyses: glucose, acetone, and alcohols.

Lavender Tube Top

Contains EDTA as anticoagulant. Used for various hematology procedures (CBC, hematocrit, etc.), cholinesterase and blood solvent determinations.

Serum Transport Vial

Plastic vial with screw cap or glass tube with teflon-lined screw cap; used for transport of serum or plasma transferred from original blood collection tubes.

PLEASE NOTE: If any specimen collection requirements are not clearly understood, or, not given, please contact the laboratory for instructions before sample collection is done.

Shipping Specimens

Contact commercial overnight carrier of your choice and ask for a overnight lab pack and tell them you need same day pick-up service of a package for overnight delivery. The airbills can be provided with the collection supplies and pre-printed for shipping to Pacific Toxicology Laboratories. Contact Client Service department for more information. Note: IF YOU ARE SHIPPING ON FRIDAY, PLEASE MARK "SATURDAY" DELIVERY ON THE FORM.

Specimen Retention

PacTox abides by all mandatory requirements for specimen storage. For specific inquiries , please contact our Customer Service Department.