Maxwell RSC- Automated DNA and RNA Purification with Integrated Quantitation

Overview

The Maxwell Rapid Sample Concentrator (RSC) Instrument is an automated nucleic acid purification system that will process up to 16 samples in a single run. Used in combination with prefilled reagent cartridges, the Maxwell RSC can purify DNA or RNA from a wide range of sample types. The intuitive graphical user interface makes the instrument easy to use, and the integrated Quantus Fluorometer lets you collect purification and quantification data in one report.

Specifications

• Processing Time: 30–60 minutes (depending on sample type and method)
• Number of Samples: Up to 16
• Weight: 24.2lb (11kg)
• Dimensions (W × D × H): 13 × 13.6 × 11.8 inches (330.2 × 345.2 × 299.7mm)
• Power Requirements: 100–240VAC, 50/60Hz, 2.5A
• Fuse: 250VAC, 2.5A, low breaking capacity, time-lag fuse (AC250V, T2.5AL, 5 × 20mm)
• UV Bulb: Average lifetime approximately 6,000 hours, length 135.9mm, diameter 16mm, 4W, 0.17A current, 29V, spectral peak F 253.7, UV output 0.9W

Instrument Standard Components

• 1 Maxwell RSC Instrument
• 1 Tablet PC preloaded with Maxwell RSC Application Software
• 1 USB Cable for connection of the Maxwell RSC Instrument to the Tablet PC
• 1 Power Cable for Maxwell® RSC Instrument
• 1 Power Cords for Tablet PC
• 1 Maxwell RSC/CSC Deck Tray
• 1 UV Bulb (installed)
• 1 Quantus™ Fluorometer and accessories
• 1 Tablet PC Holder
• 1 Quick Start Guide
• 1 Setup Guide

For more info, visit: promega.com

PAMET Membership- Everything You Need To Know

ARTICLE III

MEMBERSHIP

Section 1. Members

Medical technologists and medical laboratory technicians, duly registered by the Professional Regulation Commission-Board of Medical Technology, are qualified to become members of the Association.

Section 2. Classification of Membership

There shall be three (3) major categories of individual personal membership, which can be given voting privileges following compliance to prescribed requirements – Regular, Diplomate, and Fellow.

There shall be two (2) other categories – Associate and Honorary, with no voting privileges.

a. Regular – membership conferred to a Registered Medical Technologist (RMT).

a.1 Category A- regular membership conferred to a Registered Medical Technologist within a period of 2 years, has paid the required membership dues and has no voting rights.

a.2 Category B- regular membership automatically conferred to a Registered Medical Technologist after 2 years of active membership, has paid the required membership dues and has earned the required 20 CPE units per year. They have voting rights.

b. Diplomate – an upgraded membership, conferred by the Board of Directors through a Board Resolution, to a Regular Member of at least 7 years, with master’s degree or equivalent, along the practice of medical technology in clinical laboratory, academe, or other specialization related to health; has earned the required 20 CPE units for the year prior to application; certified to be a member of good standing and in compliance to other prescribed requirements.

c. Fellow – an upgraded membership, conferred by the Board of Directors through a Board Resolution, to a Diplomate Member of at least 4 years with doctorate degree or equivalent, along the practice of medical technology in clinical laboratory, academe, or other specialization related to health; has earned the required 20 CPE units for the year prior to application; certified to be a member of good standing; and in compliance to other prescribed requirements. Those who have been accorded the Fellow status before 1992 shall remain as Fellows of the Association.

d. Associate – membership conferred to a Registered Medical Laboratory Technician (MLT); has paid the required membership dues; and has earned the required 20 CPE units per year.

e. Honorary – lifetime membership conferred by the Board of Directors as a distinct honor for service rendered for the improvement of the medical technology profession. It is not subject to the usual membership dues and entitlement of membership benefits.

Section 3. Place of Membership

A Medical Technologist shall seek membership in the chapter nearest his/her residence or place of work. A Medical Technologist shall be a member of only one chapter. Members from the National Capital Region shall directly seek membership from the National Association. All members are deemed members of the National Association and not of local chapters only.

Section 4. Dues

Every member shall pay membership dues annually except for Honorary Membership. The dues shall cover the fiscal year and shall be paid not later than September 30 of each year to be in good standing.

Section 5 . Inactive Membership

Membership to the association is said to be inactive:

a. If the appropriate membership dues have not been paid for a period of two (2) consecutive years;

b. As a disciplinary measure after due process.

With inactive membership, entitlement to benefits is suspended.

Section 6. Re-instatement to Active Membership

Inactive Membership may be reverted to active membership after payment of all appropriate dues and penalties and after having served the prescribed disciplinary measure.

Section 7. Upgrading of Membership

Members who are qualified to upgrade for Diplomate and Fellow categories shall apply to the Committee on Membership and satisfy all prescribed requirements.

Section 8. Rights, Duties and Obligations, and Benefits of Members

Every member has the following –

Rights

a. Vote and be elected for office following prescribed qualifications and requirements;

b. Be appointed to committee(s) and other special tasks for the Association;

c. Be heard on matters pertinent to the Association;

d. Be appraised on financial and other operational matters pertinent to the Association;

e. Be entitled to due process for any complaint or case brought against the Member;

Duties & Obligations

f. To regularly comply with all requirements pertinent to membership including annual membership fee;

g. To regularly and actively participate in the affairs of the Association;

h. To regularly attend activities and functions of the Association;

i. To give recommendations/suggestions that will benefit the Association, its members and the profession.

Benefits

j. Access to continuing professional education and/or professional development program of the Association;

k. Access to information regarding medical technology and/or health care, both local, Asian and international; and

l. Seek protection or assistance on matters affecting the Member in the practice of the profession.

Section 9. Local Chapters

Local chapters may be established to help the National Association reach out to its member and help expand and consolidate its membership.

a. A local chapter is an aggrupation of at least 25 regular members in a territory approved by the National Board of Directors, depending upon the geographical and other factors in the area. The approval shall be documented through a Board Resolution.

b. The Board of Directors of each Chapter, elected by the membership of the chapter, shall be composed of nine to fifteen (9-15) members depending on the number of its membership, and who shall elect their officers from among themselves.

c. The Election shall be made every two (2) years between October 1 and November 15, in the National Election year. Term of office is two (2) years.

d. Chapter By-Laws shall adopt the By-Laws of the National Association but shall have autonomy in the distribution of the Board of Directors and Officers .

e. Prior to Chapter Accreditation, there shall be Chapter Recognition by the National Board of Directors for a minimum period of one (1) year.

f. Chapter Accreditation shall be based upon compliance to criteria set by the National Committees on Chapters and Membership.

g. Delisting from the Roster of Accredited Chapters may be done for non compliance or non performance by the Chapter for a period of four (4) years, according to criteria set by the National Committees on Chapters and Membership.

h. A delisted Chapter may be restored to the Roster of Accredited Chapters following compliance to the prescribed procedures.

Karyotyping- Definition, Principle, Preparation and Technical Procedure

Definition and Principle

Karyotyping is a laboratory procedure that allows examination of a patient’s set of chromosomes. “Karyotype” also refers to the actual collection of chromosomes being examined. Examining these chromosomes through karyotyping allows your physician to determine whether there are any abnormalities or structural problems.

Chromosomes, which are in almost every cell of your body, contain the genetic material inherited from your parents. They are composed of deoxyribonucleic acid (DNA) and determine the way that every human being develops.

When a cell divides, it needs to pass on a complete set of genetic instructions to each new cell it forms. Normally, when a cell is not in the process of division, the chromosomes are arranged in a diffuse, unorganized way. However, during division, the chromosomes in these new cells line up in pairs. In a karyotype test, which examines dividing cells, these pairs are arranged by their size and appearance, allowing a doctor to easily determine if any chromosomes are missing or damaged.

Test Applications

If you have an unusual number of chromosomes, if they are arranged incorrectly, or if they are malformed, this can be a sign of a genetic condition, such as Down or Turner syndrome.

Karyotyping can be used to detect myriad genetic disorders. For instance, if a woman has premature ovarian failure, she may have a chromosomal defect that karyotyping can distinguish. The test is also useful for identifying the Philadelphia chromosome, the presence of which can signal chronic myelogenous leukemia.

Babies can be karyotype tested before they are born to diagnose genetic abnormalities that indicate serious birth defects, such as Klinefelter syndrome, in which a boy is born with an extra X chromosome.

Materials Needed

• Chromosome medium (one bottle per student)--- KaryoMAX Peripheral Blood Karyotyping Medium. These bottles usually come in groups of 10 (each bottle containing 5 mL of media).
• Colcemid solution (10 mL bottle) --- KaryoMAX Colcemid liquid
• Giemsa stain (100 mL bottle) --- KaryoMAX Giemsa Stain Stock
• Potassium chloride solution, 0.075M (about 10 mL per student) --- KaryoMAX Potassium 
Chloride Solution, 0.075M
• Sterile 1 or 5 mL syringe21-guage needle for the syringeGreen-top vacutube21-guage multidraw needle (for vactube)15 mL centrifuge tube
• Pasteur pipetteBulb for the pasteur pipette70 percent isopropyl alcohol pad

Equipments Needed

• Centrifuge
• Glacial acetic acid (ACS grade)
• Absolute methanol (ACS grade)
• Refrigerator
• Incubator (capable of 37oC)
• Frosted glass slides

Procedure

1. Preparation of cell culture

• Using a 21-guage multi-draw needle and a green top vacutube (both supplied by the local hospital, if you are lucky), a qualified technician withdraws blood from the students.
• Prepare a sterile 5 mL syringe with a 21-guage needle.
• Wipe the top of the green top tube [Bottle with needle] (containing blood) with an isoproponal alcohol pad.
• Insert the needle on the syringe into the green top and withdraw a few milliliters of blood.
• Open the bottle of chromosome medium and place five to ten drops of blood into the medium. Sterile technique must be used because it is possible to cause major contamination during this procedure. 

2. Incubation

• Mix the medium and blood by gentle inversion and place the bottle in a preheated incubator at 37o C.
• Incubation for 70 hours
• Mix gently by inversion twice a day during incubation 

3. Stopping the cell division at metaphase

• Pre-warm the Colcemid in the incubator at 37 degree Celsius. CAUTION: Colcemid can be dangerous, so handle with care. Colcemid is a mitotic spindle inhibitor. If splashed on skin, rinse immediately and seek medical help.
• Add 0.05 mL (50 microliters) of prewarmed 37oC Colcemid to the culture. Mix gently and put the culture back into the incubator.
• Incubate for 30 to 60 minutes. 

4. Hypotonic treatment of the red and white blood cells

• Remove the blood and Colcemid solution from the [Centrifuge] incubator and mix gently.
• Put the entire contents of the bottle into a conical centrifuge tube. If conical tubes are not available, regular tubes can be used.
• Centrifuge for six minutes at 500 - 900 rpm (see notes at the end of lab regarding centrifuge speed).
• After six minutes, turn off the centrifuge and wait for a complete stop. Carefully remove the tube.
• Remove the supernate (clearish fluid on top) with a pasteur pipette. Be very careful not to disturb the button of cells on the bottom. Make sure that the bulb of the pipette is depressed before it is inserted into the test tube. Leave some fluid (anywhere from * to * mL) on the top of the button of cells. When withdrawing fluid, keep the pipette tip against the side of the test tube to avoid any shaky movements.
• Add one mL of warmed 37oC hypotonic solution to the tube. Mix by flicking the tube with your finger. Now add another nine mL of hypotonic solution. The hypotonic solution should not be in contact with the cells for more than a total of 24 minutes. Excess exposure may cause rupture of the white blood cells.
• Throughly mix all the hypotonic fluid with the cells. This is done by drawing all the mixture at the bottom of the tube into a pasteur pipette and forcing it out again. Do this two or three times to thoroughly mix.
• Place the mixed solution into the 37oC incubator for nine minutes
• The fixative solution must be made fresh. While the hypotonic solution is working, make up the fixative solution as follows: add three parts chilled absolute methanol (or as close as you can get) to one part galacial acetic acid. Both chemicals should be as pure as possible.
• After nine minutes, centrifuge for six minutes at 500 to 900 rpm.
• Remove the supernate. leaving * or * mL of fluid on top of the button of cells. At this time you probably have a small whitish or reddish film at the bottom and slightly up the side of the tube. The film contains large quantities of red blood cell debris and the enlarged white blood cells. Your entire experiment, up to this point, has been to isolate that film at the bottom of the tube. 

5. Fixing the cells

• Add 5 mL of fixative solution to the centrifuge tube.
• With a pasteur pipette, mix the fixative and button of cells by drawing the mixture into the pasteur pipette and forcing it out again. Do this three of four times. Place this solution of cells and fixative into a refrigerator for 30 minutes. Make sure the test tube is covered with aluminum foil because of the smell. The 30 minutes in a refrigerator is a minimum; actually, it is possible to keep cells in the refrigerator overnight. During this time, practice dropping water on slides (instructions to follow).
• After refrigeration, centrifuge the tube for six minutes at 500 to 900 rpm.
• Remove the supernate and add another 6 mL of cold fixative and mix as you just did in the instructions above.
• Centrifuge the tube for six minutes at 500 - 900 rpm.
• Repeat the above two steps.
• Remove the supernate leaving about * mL of fluid at the bottom of the tube. It is this remaining material that you will drop on your slides in the next section. If you cannot see any material at the bottom of the test tube, do not despair; proceed as though there is visible material present. It is often very difficult to see.

6. Making the chromosome slides

• The slide must be exceptionally clean. Use new, factory pre-cleaned, frosted slide. The chromosome separation seems to work best if the slides are chilled in the freezer first.
• Lay five or six slides next to each other on paper toweling with no separation between them.
• Withdraw the entire contents of the centrifuge tube into a pasteur pipette. Be careful not to draw the fluid any farther than necessary into the pipette. The cells have a tendency to attach to the sides of the pipette.
• From a height of about 18 inches, drop two or three drops of fluid onto each side.
• Allow the slides to dry thoroughly. In fact, the best way to 'cure' the slides are to place them in the incubator (37oC) overnight.
• Stain the slide by immersion in fresh giemsa stain for 7 - 10 minutes.
• Remove the slides from the stain and rinse in distilled water until ALL the excess stain is removed.

Sources

Kaplan, B.J. (1978) Preparation of the normal karyotype (workbook). Chicago: American Society of Clinical Pathologists.
Macgregor, H.C. & Narley, J.M. (1983). Working with animal chromosome. New York: John Wiley & Sons

m2000 RealTime System- DNA/RNA Sample Preparation and Realtime PCR Complete Automation

Product Description

Automation is the foundation for the clinical molecular laboratory to report patient results with confidence. Abbott Molecular's m2000sp for sample preparation and the m2000rt for real-time amplification and detection are the cornerstrones for this process. m2000sp is modified to m24sp in some regions especially in Asia Pacific.

The Abbott m2000 RealTime System provides automation from bar-coded laboratory tube through patient result, creating an efficient workflow for your laboratory. This automation enables laboratorians to interface where their skills best contribute to results while minimizing errors and contamination.

Abbott Molecular is committed to molecular diagnostics. Whether through innovative assay design, expanding the mSystem menu, or new system software releases, we are continuously evolving.

m2000sp: Sample Extraction Automation

• Barcoded Laboratory Tubes - Reduces transcription error and provides positive sample ID
• Precision Pipetting - Eliminates manual mixing or manipulation
• Open Mode - Flexible protocol for various sample types and volumes
• Efficient Sample Extraction - Flexible throughput options of 24 to 96 samples

m2000rt: RealTime PCR

• Real-time PCR Amplification and Detection- 5 excitation, 5 emission filters
• maxRatio Data Analysis- Multiple validity checks for improved confidence in patient results
• Minimal Maintenance- Halogen bulb replacement
• Laboratory Defined Applications- Complete flexability in defining laboratory-based real-time PCR applications

m2000 System Software: Simplified Data Management

• Intuitive User Interface- Windows XPTM
• LIS Capability- Standardized interface with LIS
• Data Archiving - Calibrator, control, and patient data logs
• Automated Quality Checks and Calibration- Provides accurate results
• AbbottLink- Remote Instrument Monitoring

For more info, visit: Abbottmolecular.com

QIAcube- Fully Automated DNA and RNA Sample Preparation

QIAcube is a fully automated sample prep using QIAGEN spin-column kits. It uses advanced technology to process QIAGEN spin columns, enabling seamless integration of automated, low-throughput sample prep into the laboratory workflow. No change of purification chemistry is required, assuring fast startup and immediate results. All steps in the purification procedure are fully automated — up to 12 samples can be processed per run.

Performance

Highly pure plasmid DNA

The QIAcube together with the QIAprep Spin Miniprep Kit enables fully automated purification of up to 20 µg molecular biology grade plasmid DNA. The fully automated purification procedure — including lysis — provides yields of plasmid DNA comparable to the manual procedure (see figure “DNA yields comparable to the manual procedure”). Purified DNA is suitable for use in routine molecular biology applications, such as fluorescent sequencing, cloning, or transfection of robust cells.

High-quality genomic DNA

Using the QIAamp DNA Blood Kit, the QIAcube enables purification of reproducible yields of highly pure genomic DNA . DNA purified using the QIAcube performs well in sensitive PCR even when large amounts of eluate are used, demonstrating the high purity of the DNA.

Efficient purification of viral nucleic acids

The QIAcube together with the QIAamp MinElute Virus Spin Kit enables efficient purification of viral nucleic acids. To evaluate the risk of sample-to-sample carryover during and between runs, the QIAamp MinElute Virus Spin procedure was subjected to rigorous testing using an alternating checkerboard setup of negative and highly positive plasma samples (1 x 108 IU/ml of a typical DNA virus). All of the highly positive samples were detected. All negative samples, in the checkerboard runs and the all-negative runs were unresponsive (see table “No sample carryover detected”).

Pure, high performance RNA

Together with the QIAcube, the RNeasy Mini Kit enables efficient automated purification of total RNA from animal cells, demonstrated by consistent RNA yields. The quality of RNA purified using the QIAcube is comparable to the manual procedure.

High-quality proteins

The QIAcube and Ni-NTA Spin Kit provide reliable purification of highly pure 6xHis-tagged proteins. Purified proteins are suitable for many applications, including functional investigations, crystallization pre-studies for determination of three-dimensional structure, assays involving protein–protein and protein–DNA interactions, and immunization to produce antibodies.

Efficient cleanup of DNA fragments

The QIAcube makes DNA cleanup easier than ever. Proven QIAquick technology together with optimized protocols enables direct purification of double- or single-stranded DNA fragments, from 100 bp to 10 kb. Primers, nucleotides, enzymes, and other impurities are efficiently removed and recovery of DNA is comparable to the manual procedure.

Principle

The QIAcube enables continued use of well-established QIAGEN spin-column kits and eliminates the need for tedious manual steps. The innovative QIAcube controls integrated components including a centrifuge, heated shaker, pipetting system, and robotic gripper. This enables the QIAcube to fully automate more than 40 QIAGEN spin-column kits. 

The QIAcube is preinstalled with a variety of protocols for purification of RNA, genomic DNA, plasmid DNA, viral nucleic acids, and proteins, plus DNA and RNA cleanup. All standard protocols in the expanding range can also be downloaded free of charge. In addition, customized protocols tailored to meet your specific application demands can also be requested. 

Procedure

The QIAcube enables purification of highly pure nucleic acids or proteins using a simple lyse, bind, wash, elute procedure. Over 40 QIAGEN spin-column kits can be automated on the QIAcube.

Unparalleled ease of use

The QIAcube takes ease of use to a new level. No external PC is required, saving valuable laboratory space. An integrated touch screen simplifies protocol selection, and clear on-screen messages guide the user through worktable setup. For increased ease of use and high process safety, labware and accessories fit onto the worktable only in the correct orientation. In addition, a fully automated load check helps to ensure that samples, reagents, and labware are correctly loaded.

New dedicated kits for DNA and RNA preps

Dedicated QIAcube Kits further simplify automated spin preps on the QIAcube and increase convenience. Kits are currently available for purification of RNA, genomic DNA, and viral RNA. Rotor-adapters supplied with the kits are preloaded with spin columns and elution tubes, delivering greater convenience and time savings. Furthermore, ease of use is increased and user errors minimized. Waste is reduced as the content of the dedicated kits is tailored to purification on the QIAcube and tubes required for the manual procedure are not included.

Applications

The QIAcube is highly suitable for academic research laboratories as well as pharmaceutical, biotechnology, and biomedical research laboratories performing applications, such as:Sequencing/sequencing analysisGene expression analysisGenotypingProteomics

For more info, visit : qiagen.com

The Clinical Laboratory Law: RA 4688

Managing clinical laboratories in the Philippines is legally guided by Republic Act 4688 or the Clinical Laboratory Law of 1966 with several Administrative Orders (AO) and Executive Orders (EO) to supplement its implementation.

The legal history of RA 4688 started on June 18, 1966 when it was approved and ratified by the president of the Philippines. The law then developed with the aid of several Administrative and Executive Orders that were issued for supplementation and regulatory guidelines in support of RA 4688.

The following Administrative and Executive Orders were issued in relation to RA 4688:

• AO 201 s. 1973
• AO 290 s. 1976
• AO 52 s. 1983
• AO 49-B s. 1988
• EO 102 s. 1999 (Redirecting the Functions and Operations of the DOH)
• AO 59 s. 2001 (Rules and Regulations Governing the Establishment, Operation and Maintenance of Clinical Laboratories in the Philippines)
• AO 27 s. 2007 (Revised Rules and Regulations Governing the Licensure and Regulation of Clinical Laboratories in the Philippines)

REPUBLIC ACT NO. 4688

REPUBLIC ACT NO. 4688 - AN ACT REGULATING THE OPERATION AND MAINTENANCE OF CLINICAL LABORATORIES AND REQUIRING THE REGISTRATION OF THE SAME WITH THE DEPARTMENT OF HEALTH, PROVIDING PENALTY FOR THE VIOLATION THEREOF, AND FOR OTHER PURPOSES 

Section 1. Any person, firm or corporation, operating and maintaining a clinical laboratory in which body fluids, tissues, secretions, excretions and radioactivity from beings or animals are analyzed for the determination of the presence of pathologic organisms, processes and/or conditions in the persons or animals from which they were obtained, shall register and secure a license annually at the office of the Secretary of Health: provided, that government hospital laboratories doing routine or minimum laboratory examinations shall be exempt from the provisions of this section if their services are extensions of government regional or central laboratories.

Sec. 2. It shall be unlawful for any person to be professionally in-charge of a registered clinical laboratory unless he is a licensed physician duly qualified in laboratory medicine and authorized by the Secretary of Health, such authorization to be renewed annually. 

No license shall be granted or renewed by the Secretary of Health for the operation and maintenance of a clinical laboratory unless such laboratory is under the administration, direction and supervision of an authorized physician, as provided for in the preceding paragraph. 

Sec. 3. The Secretary of Health, through the Bureau of Research and Laboratories shall be charged with the responsibility of strictly enforcing the provisions of this Act and shall be authorized to issue such rules and regulations as may be necessary to carry out its provisions. 

Sec. 4. Any person, firm or corporation who violates any provisions of this Act or the rules and regulations issued thereunder by the Secretary of Health shall be punished with imprisonment for not less than one month but not more than one year, or by a fine of not less than one thousand pesos nor more than five thousand pesos, or both such fine and imprisonment, at the discretion of the court. 

Sec. 5. If any section or part of this Act shall be adjudged by any court of competent jurisdiction to be invalid, the judgment shall not affect, impair, or invalidate the remainder thereof. 

Sec. 6. The sum of fifty thousand pesos, or so mush thereof as may be necessary, is hereby authorized to be appropriated, out of any funds in the National Treasury not otherwise appropriated, to carry into effect the provisions of this Act. 

Sec. 7. All Acts or parts of Acts which are inconsistent with the provisions of this Act are hereby repealed. 

Sec. 8. This Act shall take effect upon its approval. 

Approved: June 18, 1966

Bacillus anthracis- Characteristics and Morphology

image courtesy of textbookofbacteriology.net

Bacillus species are large motile, facultative anaerobic, gram positive bacilli with a central spore. The spore is quite resistant to extreme conditions and can survive in nature for prolonged periods of time. 

B. anthracis is non-motile and in Gram stain is often seen in chains. The virulent forms of B. anthracis is more likely to be surrounded by a capsule. The organism can be cultured as large colonies on blood agar plates within 24 hours, often resembling a "Medusa head" (irregular appearance to the colony with swirling projections).

Creatinine Clearance Test

The creatinine clearance test compares the level of creatinine in urine with the creatinine level in the blood. It is an imperfect measure of glomerular filtration rate. The use of creatinine to estimate glomerular filtration rate is based upon three assumptions: (1) creatinine is filtered through the glomerulus, (2) relatively low amounts of creatinine are reabsorbed through the nephron tubule, and (3) creatinine production is constant overtime. Although creatinine can provide a rough estimate of glomerular filtration rate, error may be encountered. Such factors as increased tubular reabsorption of creatinine, reduced creatinine generation from muscle tissue, and dietary changes in nitrogenous compounds may affect creatinine clearance.