|Questions Regarding the Endosafe®-PTS
|Is the PTS licensed by the FDA?
|Yes, Charles River Laboratories received FDA approval for the PTS in
July 2006. With this approval, the PTS is an approved LAL testing method
for in-process and end product release.
|What is the QC procedure for cartridges?
|The cartridges are potency tested, spike recovery is performed and the
calibration code is determined. The calibration code contains all of the
cartridge test parameters that were determined during potency testing, as well
as the archived curve for that batch of cartridges. The calibration code is
then verified with an additional test cartridge.
|How is the archived standard curve determined?
|Five (5) cartridges of each standard curve concentration are run to obtain
the average reaction time for each standard; five (5) cartridges are used for
the negative water control; ten (10) cartridges are used to determine the spike
concentration; and one (1) cartridge is used for potency and calibration code
|What are the QC requirements for release of the test
|The archived curve is determined, as mentioned above, with acceptability
requirements of <25% Coefficient of Variation between replicates and a
Correlation Coefficient (R) of = 0.990. Recovery of the spiked values in the
potency verification phase must be within 50% to 200%.
|How is the potency of the spike determined?
|LAL Reagent Water is tested on 10 test cartridges, and the mean reported
value is calculated and becomes the archived spike concentration for that lot
of cartridges. This value may be different for each batch of cartridges.
|How is the spike recovery calculated on the
The % spike recovery can be calculated by dividing the reported spike EU/mL
value by the archived spike concentration determined during potency testing and
then multiplying by 100. The "Recovery Factor" displayed on the test
report is the conversion factor for the actual spike concentration. It must be
used to calculate the actual spike concentration for that particular lot of
cartridges by multiplying it by the midpoint of the archived standard
0.577 EU/mL (Reported spike value) > x 100 =
111.0% spike recovery
0.52 EU/mL (Archived spike concentration)
|Why is the positive product control not 0.5 EU/mL for a
5 to 0.05 EU/mL curve?
|The USP says to select an endotoxin concentration at or near the middle of
the endotoxin standard curve. The cartridge is spiked with a predetermined
nanogram amount of CSE during the filling operation. The EU/ng value is then
determined during release testing using the government Reference Standard
|Can the PTS data be downloaded directly to a regular
|Charles River offers a battery powered, rechargeable thermal printer that
works directly with the reader as well as an Epson printer that prints in black
ink on receipt paper for a long-lasting test record. To download data to a
separate printer, we recommend using the PTS Logger software that is included
with the purchase of the reader.
|Can multiple tests be printed at one time?
|With the PTS thermal printer or the Epson printer attached to the reader,
you can print results from the last test that was run, print results by date,
or print all the results stored in the reader (up to 100).
|Can I export the data to Excel?
|Not directly. There is the possibility that data that is downloaded from
"Hyper Terminal" may be exported to Excel, but we have no experience
|What types of products have been tested with the
|A range of products have been tested with the PTS, including biologicals
(Human Serum Albumin), raw materials (saline, buffers), parenterals, water
systems, and medical device extracts. Since the PTS cartridges are loaded with
licensed LAL, any product that is tested by other LAL methods can be tested
with the PTS.
|Will the PTS read hot or cold samples?
|Extreme temperature may affect results and, therefore, we recommend that
you treat your PTS samples as you would any other LAL sample. Bring test sample
and test cartridge to room temperature before using. Load the cartridge into
the reader and wait until "Add sample" is on the display before
delivering sample to cartridge.
|How does the cost compare to other LAL
|At first glance, it may appear that the cartridges are more expensive than
other quantitative LAL methods. Keep in mind, however, that all the reagents
needed to run the test - lysate, endotoxin, and LRW - are already included in
the cartridge. The standard curve has also been performed already, which
typically requires a minimum of 6 wells and 2 additional wells for negative
water controls. So one test run with the PTS really includes 8 wells for the
curve and 4 wells for the samples and negative controls - a total of 12 wells.
The advanced technology of the test also saves considerable time on labor as
|Do you have a cartridge that has a lower sensitivity
|Yes, the lowest sensitivity now available is 0.01 EU/mL.
|What is the maximum time setting for the assay to
|The assay time is dependent upon the specific lot of cartridges and their
sensitivity. The time is determined by the calibration code and can not be set
by the user. A typical assay is takes approximately 15-20 minutes to
|Will you have a system that will fit more than one
|We are considering many different configurations for expanded models of the
|How can I calibrate my instrument on a regular basis?
How often should I?
|The factory calibration certified at the time of initial shipment is valid
for one year. Re-certification cannot be done by a customer, so Charles River
offers a calibration re-certification service to make sure the reader is
performing as expected.
|How precise and accurate is the test?
|The PTS meets the same accuracy parameters as an LAL test method.
|Is data generated from the PTS comparable to kinetic or
gel clot LAL assays?
|Yes. The PTS is a modified 2-step kinetic assay that utilizes FDA-licensed
LAL reagent. Charles River is using the same government reference standard in
potency testing to determine the calibration code. The same standards are used
to release kinetic and gel clot LAL.
|What is the expiration of the cartridges?
|The current expiration period is one (1) year.
|How can you tell how much charge the battery has
|It is important to keep track of the battery life so that it does not
expire unexpectedly. Charging it overnight should prevent a loss of power. When
the reader is turned on, the battery will display the % charge it holds. If the
reader is plugged into the charger and then turned on, it will display Bat:
Charging with a percentage that slowly increases with time. If it is not
plugged into the charger, it will display Bat:Discharging,
and the percentage will slowly decrease with use. To view this % charge at any
time, select Menu 6 to reset the reader and the % charge will be displayed. We
do have plans to add a power bar to the screen to provide a constant visual
|Do I need to calibrate the mini-pipettor? Does it come
|There is no need to calibrate the mini-pipettor if your QA group accepts
the Certificate of Quality that verifies calibration. The manufacturer
specifies that the mini-pipettor performs at ± 5% accuracy and ± 3% precision,
and this document can be furnished upon request.
|What is the warranty and maintenance program?
|Upon purchase, the PTS comes with a warranty that is good for one year.
Repairs will be made at no charge during that period. If desired, there is also
an Extended Warranty program that must be purchased within the first year of
ownership and will include a warranty for 4 additional years after the initial
warranty has expired.
|General Questions Regarding Endotoxin Testing
|Is Charles River new to endotoxin testing?
|Charles River Endosafe has been in the endotoxin testing business since it
was founded by Dr. James F. Cooper in 1987. Dr. Cooper is one of the pioneers
in the LAL field and has helped Endosafe become the worldwide market
|Are your reagents FDA approved?
|All Endosafe lysate, as well as the facility they are produced in, are FDA
|What is your shipping policy?
|Charles River ships all orders Monday through Thursday to arrive to the
customer the following day.
|Do you have products for oven validation?
|Charles River offers the most extensive line of products for oven
validation in the industry. Our endotoxin indicators are sold in 6 different
concentrations ranging from 2,000 to 10 million EU / vial.
|Do you sell your own automated LAL system?
|Charles River sells a system that consists of an incubating plate reader
along with Endosafe's endotoxin measuring and database trending software
package. The system comes fully qualified along with a manual for easy in-house
|Is the Endosafe software validated?
|Our EndoScan-V is the first endotoxin-specific software that addresses the
21 CFR Part 11 requirement for validation. Both EndoScan-V and the BioTrend
3.0b database trending software are verified and validated consistent with
USFDA and CE mark requirements and comply with CFR 820.30.
|Are the horseshoe crabs killed or injured during the
|The horseshoe crabs are used during harvesting by puncturing the septum on
the underside of the animal. The animal will only give as much blood as it can
afford (about 25%) before it shuts off the blood supply. This ensures that the
animal will not bleed to death. The horseshoe crab is then released back into
the water. The mortality rate for the crab as a result of the process is less
|Why does your lysate have different
properties than the competition?
|Although all LAL reagents utilize the enzyme found naturally in the
horseshoe crab to detect endotoxin, it is the total LAL reagent formulation
that controls its performance. Such qualities as stability, sensitivity, speed
and linearity are all dependent upon the individual manufacturer's LAL
formulation. This formulation also controls inhibition / enhancement
properties. Since its inception, Endosafe has been dedicated to developing LAL
reagents that are superior to those offere by competitors.
|What are the best ways to overcome interference
|Inhibition can best be overcome by using an LAL reagent that is designed
for testing complex pharmaceutical products and raw materials. Endosafe lysate
is the most recently approved in the industry, allowing us to improve upon
previous interference problems.
|Do you have a method to trend data from the kinetic
|Yes, Endosafe now offers Microtrend, a new database trending package that
allows LAL customers to track and trend the various data that is generated and
automatically downloaded from the EndoScan-V endotoxin measuring software.
|Is chromogenic better than turbidimetric for LAL
|It is a misconception that chromogenic LAL is better than turbidimetric
LAL. Chromogenic LAL became popular because its high sensitivity (.005 EU/ml)
and 1:1 product to lysate ratio allows users to dilute further to overcome
inhibition. Recent innovations by Endosafe have produced a turbidimetric lysate
with the properties of a chromogenic reagent with a turbidimetric price.
|What kind of technical assistance does Endosafe offer
|Endosafe provides technical support via phone (800-762-7016), email, in-house troubleshooting,
seminars, and workshops on a variety of topics such as methods development,
SOPs, and regulatory guidance.
|Does Endosafe distribute internationally?
|Endosafe products are available internationally through a collection of
distributors. To get a list of these distributors, click