Make 75 ml of a 2M HCl solution from the 5M solution you have.
V1 C1 = V2 C2
75 x 2 = X x 5
150 = 30 x 5
X = 30
30 ml of a 5M solution brought up to 75 ml with diluent = 2 M HCl
How many grams are needed to make 2 L of 3 M HCl ? HCl gmw is 36.5
g= M x L x gmw
X =
3M x 2L x 36.5
X = 219
219 g HCL brought up to 2 L = 3M HCl
How much 4 M NaCl can be made using 45g NaCl? gmw NaCl is 58.5
L = g/ M divided by gmw
= 45 g divided by 58.5
4 M
L= 0.2
45g NaCl brought up to 0.2 L = 4M NaCl
What is the Normality of a 0.75 M solution of AlCl3 ? AlCl3 valence is 3
N= M x valence
0.75 x 3 = N
N= 2.25
Make 1.5 mL of a 1:3 dilution.
proportion A = C B D
1 = x 3 1.5
X = 0.5
0.5 SV + 1.0 DV = 1.5 TV
You combined 1 ml serum with 1 ml of saline. What dilution did you create?
SV + DV = TV
1ml + 1 ml = 2 ml
1 : 2
Put 0.5 ml of saline in 3 tubes. Place 0.25 ml patient sample in tube 1 and mix. Take 0.5 ml from tube one and transfer to tube 2 and mix. Do the same for tube 3. What are the dilutions in each tube?
Tube 1- 1: 3
Tube 2- 1:6 (1:2 of a 1:3)
Tube 3- 1: 12 (1 :2 of a 1:6)
Make 150 ml of buffer usung 3 parts NaCl and 2 parts water.
C / (A + B)= V
150/ (3 + 2) = 30
150 / 5 = 30
90 ml NaCl + 60 ml water = 150 ml buffer
Usual site of venipuncture-
Antecubital
Red, gold, red/gray collection tubes are used for-
Chemistry analysis- they have lithotrypsic gel to separate serum, they contain no anticoagulant, are used for serum
Green collection tubes are used for-
chemistry- They have the anticoagulant
sodium or lithium heparin. Plasma comes from these tubes
Plasma comes from blood that-
has not been allowed to clot
Serum comes from blood that-
has been allowed to clot
The # 1 analyte checked for is-
glucose
electrolytes and protein are common also
Urine specimens are often checked in chemistry lab for
drug screen, pregnancy
CSF is checked in chemistry for-
protein, glucose, lactate
Hemolysis after centrifugation is usually caused by-
rough stick
Icterus after centrifugation is usually caused by-
Liver (yellow)
Seeing Lipemia after centrifugation is caused by-
Triglycerides (whitish)
Example of a corrosive chemical-
HCl
Example of a toxic chemical-
disinfectant
Example of a carcinogenic chemical-
benzene
Example of an ignitable chemical-
acetone
Example of an explosive chemical-
sodium azide
Define biohazard-
infectious material
The #1 lab accident is-
needle sticks
Viability of Hepatitus B in spills
7 days
Viability of HIV in spills-
3 days
If a tube breaks in the centrifuge allow it to sit-
1/2 hour to allow fine droplets to settle
Name 2 blood bourne pathogens of importance-
HIV and Hepatitis C
Name an air bourne pathogen of importance
Mycobacterium tuberculosis (TB)
Define nosocomial infection
Hospital acquired
Used to decontaminate spills and glassware before washing-
0.5% household bleach
parameters for autoclaving
121 degrees C at 15# pressure for 30-60 minutes
Type of water used for reagent calibration or controls
Reagent grade water
Detects lab problems before during & after testing
Quality assurance
Quality factors outside the lab
Pre-analytical
Lab control factors
analytical
Used to set instrument parameters
calibrators
Used to find reference ranges or as a cross check
quality controls
internal control-
used within a single laboratory
external control-
prepared by survey teams such as proficiency testing or surveys
quality factors affecting patient recordkeeping or patient results
post analytical factors
The closeness with whichresults agree with a known true value
accuracy
determines the accuracy of a procedure
mean
determines the precision of a procedure
Co- efficient of variation - CV
error that occurs solely by chance
random
error that affects all samples
systematic
Gaussian Distribution Curve
bell shaped curve
Another name for +/- 1 SD
2 STD range
Another name for +/- 2 SD
4 STD range OR 95% interval
Another name for +/- 3 SD
6 STD range
What range is considered acceptable for all test results in the lab?
+/- 2SD
The average of a group of numbers
mean
Another name for Standard deviation
confidence limits
Which Westgard rule is known as the warning rule?
12s
All Qc results are distributed on the same side of the mean for 6 or 7 days
Shift
All QC results consistantly either decrease or increase for 6 or 7 days
Trend
The patients most recent result compared to the previous value
Delta Check
The smallest concentration that can be detected accurately
Analytic sensitivity
The proportion of patients that test positive for a disease
Diagnostic sensitivity
The proportion of patients without the disease that test negative
diagnostic specificity
Absorbance is directly proportional to concentration
Beer's Law
A=abc
<400 nm (light)
Ultraviolet
400-800 nm (light)
Visual
> 800 nm (light)
Infrared
Required conditions for Beer's law to be true
homogenous solution
monochromatic light source
dilute enough to read
Isolates a wavelength of light
slit
width of the slit
bandpass
holds sample for photometry
cuvette
light which passes thru the cuvette
percent transmission
light which remains in the cuvette
absorbance
define bandpass
the whole amount of the wavelength
light source for photometer
tungsten lamp (white light)
halogen or quartz ( UV)
Directs and focuses light in a photometer
culminating lens
Breaks the light into individual wavelengths
monochromator-
It has 3 parts:
1. glass filters (colorimeter)
2. prism ( Spectrophotometer)
3. diffraction grating (spectrophotometer)
detects the amount of light transmitted and converts it to electrical energy
photodetector
converts electrical energy into a usable display
readout device
standard curves must consist of
at least 2 standards
3 types of blanks used on spectrophotometer
1. Reagent blank - reagent only, no sample
2. water blank - water only, used with clear reagents to save money
3. sample blank - sample plus clear reagent or water ( subteacts the color of the sample)
formula for Absorbance
A = 2-log%T
Graphed on linear graph paper
A is directly proportional to Concentration (C)
A is inversely proportional to Transmittance (T)
mathematical proof of linear standard curve
K constant
K= Absorbance std divided by Concentration std (for each standard)
Colorimetric Formula
Conc. of Unknown = A unknown divided by A standard X concentration std
K Constant
K= AbsCons for each standard
define the differences between qualitative and quantitative results