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Lab Resources

  • How to Setup a Medical Lab
    Lab Advisory Can Help
    1. Determine the complexity of the tests you will perform in your laboratory.
      • CLIA-waived tests do not require Proficiency Testing participation, but you must follow the manufacturer’s directions for the tests.
      • Non-waived (Moderately or High Complexity tests) require Proficiency Testing participation, specific personnel standards, compliance with all CLIA requirements, and an on-site inspection every two years.
    2. Apply for a CLIA certificate by completing and submitting the CMS-116 form.
      For CLIA-waived testing:
      • Select a Certificate of Waiver

      For Moderate and High complexity testing options you can select:
      • Certificate of compliance if you choose a government inspection.
      • Certificate of accreditation if you choose an accrediting agency and participate in their program.
    3. Enroll in an approved Proficiency Testing Program for all regulated analytes or an alternate proficiency testing method for the non-regulated analytes in your test menu.
    4. Follow specific requirements for new laboratory equipment startup based on test complexity level.
      • Adhere to the manufacturer’s requirements
      • Perform validation and verification studies for Moderate or High complexity tests.
    5. Establish and implement a Policy and Procedure manual.
    6. Establish and implement a Quality Control and Quality assurance program.
    7. Select qualified and competent laboratory testing personnel.
    8. Offer your laboratory staff proper training with equipment and record keeping.
    9. Properly document and retain all testing staff trainings, Quality Control, maintenance, calibrations, validation studies, patient test results, proficiency testing performance, and corrective action.
    10. Always follow Good Laboratory Practices.
  • Lab Math
    Calculation of "G" or RCF (Relative Centrifugal Force)

    RCF is dependent on the speed of the rotor and the distance from the centre of the motor drive shaft to the base of the sample tube. Manufacturers will give you the maximum speed and RCF of the rotor and its radius. For any speed other than maximum, you need to calculate the RCF.


    If you do not know the radius of the rotor, you will have to measure this. Sometimes this may entail a little bit of guesswork in the case of an angle rotor. The radius is measured from the centre of the rotor to the point that would be the bottom of the sample tube. Take into account, inserts and any tube cushions.


    Insert the figures into the formula below or use a nomogram chart, if you have one, with a ruler on two values to determine the third. RCF and radius to obtain speed or radius and speed to obtain RCF.

    Nomogram for converting maximum relative centrifugal force (RCF, i.e., g-force) to RPM.
    www.aquaticpath.umd.edu/nomogram.html
    www.beckman.com/resourcecenter/labresources/centrifuges/rotorcalc.asp

    Coefficient of Variation

    Allows comparison of nonidentical data sets, i.e. two different procedures, etc., by expressing the standard deviation of each set as a percentage of the mean. CV is expressed as a %.


    The formula is: CV=(SD/X) x 100, where SD= the standard deviation of a procedure and X= the mean.


    Procedures with increasing CV values demonstrate decreased precision, since this reflects greater variability among the replicate samples.

    Slope-Intercept Formula

    y = mx + b


    where m and b designate constants (the variable y is multiplied by the constant 1, which as usual is not explicitly written). The origin of the name "linear" comes from the fact that the set of solutions of such an equation forms a straight line in the plane. In this particular equation, the constant m determines the slope or gradient of that line; and the constant term b determines the point at which the line crosses the y-axis.


    Mean

    The mean is calculated by adding all of the values, and dividing by the number of values. The formula is:


    For example, suppose you wanted to find the mean of the values 4, 6, 2, 8, and 5. The mean is:


    X = mean
    n = the- number of data points in set (total number of measurements)
    Σ = the sum of
    Xi = each measurement


    Standard Deviation


    The standard deviation (abbreviated s or SD) is calculated according to the following formula:


    That is, calculate the deviation from the mean for each point, square those results, sum them, divide by the number of points minus one, and finally take the square root. For example, the deviations from the mean in the above example are -1, 1, -3, 3, and 0. The squared deviations are 1, 1, 9, 9, and 0. The standard deviation is therefore:


    The standard deviation will be larger if the data are spread out and smaller if the data are closely clustered about the mean.


    X = each data point
    n = the number of data points in set (total number of measurements)
    Σ = the sum of
    S = standard deviation
    √ = square root
    X = mean
    Xi = each measurement


    Creatine Clearance

    (Urine creatinine X Urine volume) / (Serum creatinine X min. of duration) = (mL) / (min)


    This value is then corrected for body surface area:

    Creatinine Clearance = ((mL) / (min)) x ((1.73 m2) / (Patient's surface area (m2)))


    OR

    Urine Volume (mL/24 hours) / 1440 minutes per 24 hrs x urine creatinine/ serum creatinine x 1.73/ patient’s surface area


    24 Hour Urine Creatinine
    Urine creatinine (mg/dL) x urine volume (mL/24 hrs) x 1dl/100 ml

    24 Hour Protein
    Urine Protein (mg/dL) x urine volume (mL/24 hrs) x 1dl/100 ml


    Corrected Ratio of blood to anticoagulant (the citrate concentration must be adjusted in patients who have hematocrit values above 55%.
    C = Concentration
    C = 1.85 x0.001 (100-HCT) x volume of blood
    For a 4.5 ml draw, C = 1.85 (0.001) (4.5) (100-HCT)
    C = 0.008325 (100-HCT)

    Example: HCT= 65 in a 4.5 ml draw

    C = 0.008325 (100-65)
    C = 0.008325 (35) = 0.29 of sodium citrate needed
    0.50 – 0.29 = 0.21 sodium citrate to be removed from a 4.5 ml tube


    Chol/HDL Ratio
    The total cholesterol to HDL cholesterol ratio (total chol/HDL) is a number that is helpful in estimating the risk of developing atherosclerosis. The number is obtained by dividing total cholesterol by HDL cholesterol. (High ratios indicate a higher risk of heart attacks, whereas low ratios indicate a lower risk).

    Chol/HDL ratio = Chol/ HDL


    Free Thyroxine Index Formula
    The FTI tells how much T4 is present compared to the thyroxine-binding globulin. The FTI can help tell if abnormal amounts of T4 are present because of abnormal amounts of thyroxin-binding globulin.
    FTI = T3U x T4

    100     % Error
    % error = actual value - theoretical value X 100
    theoretical value

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Consultant Directory

Consultants with Laboratory Advisory Bureau are seasoned professional clinical lab scientists with expertise and practical knowledge in the clinical laboratory field. A choice for Laboratory Advisory Bureau is a choice not only for our services, but the experience that our team is able to bring into the mix.

Laboratory Advisory Bureau's technical laboratory consultants strive to be professional, courteous and cooperative. We at Laboratory Advisory Bureau want to assist our clients with any questions and technical problems that might arise.

Noe Medina, BS.,TC(L.A.B)
Owner
956-358-0463

Rosie Munoz, BS.,MT (ASCP)
Charter Member of ACLTC

Giancarlo Lopez, BS.
Laboratory Advisory Bureau Administrator

Christine Armenda, BS., MT (ASCP)