K Number

Device Name

CD 19 R-PE, CD19 TRI-COLOR MONOCLONAL ANTIBODY

Manufacturer

CALTAG LABORATORIES, INC.

Date Cleared

1996-11-25

(54 days)

Product Code

GKZ

Regulation Number

864.5220

Intended Use

CALTAG CD19 R-PE and CD19 TRI-COLOR are fluorochrome conjugated monoclonal antibody reagents that may be used to enumerate CD19+ lymphocytes in human peripheral blood by flow cytometric methods.

Device Description

The CALTAG CD19 R-PE and CD19 TRI-COLOR monoclonal antibodies bind to the surfaces of viable blood cells that express the CD19 antigen. To identify cells bearing the CD19 determinant, peripheral blood leukocytes are incubated with the monoclonal antibody, and washed to remove unbound antibody. Prior to removal of unbound antibody, lysis solution is added to lyse red blood cells. An appropriate fixative solution is added to lysed and washed cells. Stained and fixed cells are subsequently analyzed by flow cytometric methods.

More Information

Contact

Type

Center

Panel

Date Received

Product Code

Subsequent Product Codes

Applicant Name (Manufacturer)

Device Name

Decision

Street 1

Street 2

City

State

Country Code

ZIP

Postal Code

Class Advise Committee

SSP Indicator

Third Party Reviewed

Expedited Review

Predicate Devices

Coulter CD19 RD1 Monoclonal antibody, Coulter CD19 FITC

Reference Devices

Not Found

AI/ML (Artificial Intelligence / Machine Learning)

No
The summary describes a monoclonal antibody reagent used for flow cytometry, which is a standard laboratory technique. There is no mention of AI or ML in the device description, intended use, or performance studies. The analysis is based on antibody binding and flow cytometry measurements, not algorithmic interpretation of complex data.

Therapeutic

No
This device is a diagnostic reagent used to enumerate CD19+ lymphocytes, not to treat a condition.

Diagnostic

Yes

This device is used to enumerate CD19+ lymphocytes in human peripheral blood, which is a measurement or indicator for assessing physiological or pathological conditions, thus fitting the definition of a diagnostic device.

SaMD (Software as a Medical Device)

The device description clearly indicates that the device is a physical reagent (monoclonal antibodies) used in a laboratory process (flow cytometry) to stain blood cells. It is not a software program.

IVD (In Vitro Diagnostic)

Yes, this device is an IVD (In Vitro Diagnostic).

Here's why:

Intended Use: The intended use explicitly states that the reagents "may be used to enumerate CD19+ lymphocytes in human peripheral blood by flow cytometric methods." This is a diagnostic purpose, as it involves analyzing a biological sample (human peripheral blood) to obtain information about a patient's health status (the number of CD19+ lymphocytes).
Device Description: The description details how the antibodies bind to cells in a biological sample and how the sample is processed for analysis. This process is typical of in vitro diagnostic procedures.
Anatomical Site: The analysis is performed on "Human peripheral blood," which is a biological sample taken from the body.
Performance Studies: The document includes performance studies (Expected Value, Specificity, Reproducibility, Correlation) that are designed to demonstrate the analytical performance of the device when used with biological samples.
Predicate Device(s): The mention of predicate devices (Coulter CD19 RD1 Monoclonal antibody and Coulter CD19 FITC Monoclonal antibody) which are also IVDs, further supports the classification of this device as an IVD.

The device is used in vitro (outside the body) to analyze a biological sample for diagnostic purposes.

PCCP (Predetermined Change Control Plan) Authorized

N/A

Overview

Intended Use / Indications for Use

CALTAG CD19 R-PE and CD19 TRI-COLOR are fluorochrome conjugated monoclonal antibody reagents that may be used to enumerate CD19+ lymphocytes in human peripheral blood by flow cytometric methods.

Product codes

864.5220

Device Description

Mentions image processing

Not Found

Mentions AI, DNN, or ML

Not Found

Input Imaging Modality

Flow Cytometry

Anatomical Site

human peripheral blood

Indicated Patient Age Range

Not Found

Intended User / Care Setting

Not Found

Description of the training set, sample size, data source, and annotation protocol

Not Found

Description of the test set, sample size, data source, and annotation protocol

Not Found

Summary of Performance Studies

Non Clinical Tests and Clinical Tests were performed.

Non Clinical Tests:

Expected Value Data: Blood samples were collected from a total of 155 apparently healthy normal donors in an age range of 16 to 72 with a mean age of 41. Samples were collected and analyzed in each of three independent laboratories. An approximately equal number of males and females were collected and analyzed in each laboratory. The normal donor population included members of differing ethnic origins, including adult Caucasian, Black, Oriental and Hispanic. Donors were from geographically diverse areas of the United States, including the Western, Eastern and SouthCentral regions. Blood samples collected from each donor were stained with the CALTAG CD19 R-PE and CD19 TRI-COLOR monoclonal antibodies.
Specificity Data: Blood samples were obtained from healthy normal donors of Caucasian, Black, Hispanic and Oriental ethnic origins. Samples of each donor were stained with CALTAG CD19 R-PE and CD19 TRI-COLOR monoclonal antibodies. Cells contained in the lymphocyte, monocyte and granulocyte regions were selected for analysis. Separate samples from the same donors were prepared for analysis of red blood cells and platelets and stained with each of the CALTAG monoclonal antibodies. Specific and/or nonspecific antibody Fc binding to monocytes in a patient sample can be excluded by proper gating on lymphocytes on the flow cytometer.
Reproducibility Data (Intra-lab): Intra-lab reproducibility was determined by performing 10 replicated determinations for each antibody in each of three ranges; high, medium and low, totaling 30 determinations for each form of CD19. The 10 determinations for each range were performed by staining, processing and analysis of 10 separate samples. Lymphocytes were selected for analysis of percent cells stained. Anticoagulated blood was obtained from an abnormal donor expressing a high percentage of CD19+ cells, and mid/low range samples were prepared by adding known CD19- cells. The study was performed in each of three independent laboratories.
Reproducibility Data (Inter-lab): Inter-lab reproducibility was determined by performing 10 replicated determinations for each antibody in each of three ranges; high, medium and low, totaling 30 determinations for each form of CD19. The 10 determinations for each range were performed by staining, processing and analysis of 10 separate samples. Lymphocytes were selected for analysis of percent cells stained. The study was performed in each of three laboratories. All laboratories stained and analyzed blood samples from the same blood donors. Lysed unstained samples containing cells in the appropriate ranges were prepared by one of the participating laboratories for staining and analysis.

Clinical Tests:

Correlation Data: The correlation study was performed on 175 donors, including 155 normal and 20 abnormal donors. Comparisons were made between CALTAG CD19 R-PE and Coulter CD19 RD1, CALTAG CD19 R-PE and Coulter CD19 FITC, CALTAG CD19 TRI-COLOR and Coulter CD19 RD1, CALTAG CD19 TRI-COLOR and Coulter CD19 FITC, and CALTAG CD19 TRI-COLOR and CALTAG CD19 R-PE.

Key Metrics

Expected Values (from Non-Clinical Tests, n=155 healthy normal donors):

CD19 R-PE: mean % positive = 13.0, S.D. = 4.2 ($\pm$2 S.D.), Range = 5-21
CD19 TRI-COLOR: mean % positive = 13.9, S.D. = 5.0 ($\pm$2 S.D.), Range = 4-24

Reproducibility Data - Intra-lab (Site 1 representative data):

CD19 R-PE:
- high: mean % positive = 66.6, S.D. = 0.4, % CV = 0.5, n = 10
- mid: mean % positive = 46.7, S.D. = 0.8, % CV = 1.6, n = 10
- low: mean % positive = 14.9, S.D. = 0.6, % CV = 4.3, n = 10
CD19 TRI-COLOR:
- high: mean % positive = 65.4, S.D. = 0.7, % CV = 1.0, n = 10
- mid: mean % positive = 46.1, S.D. = 0.6, % CV = 1.3, n = 10
- low: mean % positive = 15.5, S.D. = 0.4, % CV = 2.7, n = 10

Correlation Data (n=175 donors):

CALTAG CD19 R-PE vs. Coulter CD19 RD1:
- mean % positive (CD19 R-PE) = 16.4
- mean % positive (CD19 RD1) = 16.2
- r2 value = 97.7
- slope = 0.92
- Y intercept = 1.30
- Linear regression: y = 1.30 + 0.92x
CALTAG CD19 R-PE vs. Coulter CD19 FITC:
- mean % positive (CD19 R-PE) = 16.4
- mean % positive (CD19 FITC) = 16.7
- r2 value = 96.3
- slope = 0.93
- Y intercept = 0.69
- Linear regression: y = 0.69 + 0.93x
CALTAG CD19 TRI-COLOR vs. Coulter CD19 RD1:
- mean % positive (CD19 TRI-COLOR) = 17.1
- mean % positive (CD19 RD1) = 16.2
- r2 value = 96.7
- slope = 0.92
- Y intercept = 2.14
- Linear regression: y = 2.14 + 0.92x
CALTAG CD19 TRI-COLOR vs. Coulter CD19 FITC:
- mean % positive (CD19 TRI-COLOR) = 17.1
- mean % positive (CD19 FITC) = 16.7
- r2 value = 97.4
- slope = 0.94
- Y intercept = 1.36
- Linear regression: y = 1.36 + 0.94x
CALTAG CD19 TRI-COLOR vs. CALTAG CD19 R-PE:
- mean % positive (CD19 TRI-COLOR) = 17.1
- mean % positive (CD19 R-PE) = 16.4
- r2 value = 97.6
- slope = 0.99
- Y intercept = -0.56
- Linear regression: y = -0.56 + 0.99x

Predicate Device(s)

Coulter CD19 RD1 Monoclonal antibody, Coulter CD19 FITC

Reference Device(s)

Not Found

Predetermined Change Control Plan (PCCP) - All Relevant Information

Not Found

Regulation Number and Section

§ 864.5220 Automated differential cell counter.

(a)
Identification. An automated differential cell counter is a device used to identify one or more of the formed elements of the blood. The device may also have the capability to flag, count, or classify immature or abnormal hematopoietic cells of the blood, bone marrow, or other body fluids. These devices may combine an electronic particle counting method, optical method, or a flow cytometric method utilizing monoclonal CD (cluster designation) markers. The device includes accessory CD markers.(b)
Classification. Class II (special controls). The special control for this device is the FDA document entitled “Class II Special Controls Guidance Document: Premarket Notifications for Automated Differential Cell Counters for Immature or Abnormal Blood Cells; Final Guidance for Industry and FDA.”

Summary

Image /page/0/Picture/0 description: The image shows the logo for CALTAG LABORATORIES. The logo is in black and white, with the word "CALTAG" in large, bold letters on top. Below "CALTAG" is a horizontal line, and below the line is the word "LABORATORIES" in smaller, but still bold, letters. The logo is simple and professional.

K963954

510(K) SUMMARY SUMMARY OF SAFETY AND EFFECTIVENESS DATA

NOV 25 1996

CD19 R-PE, CD19 TRI-COLOR Mouse Monoclonal Antibodies To Human Cell Surface Antigens by Flow Cytometry

NAME AND LOCATION OF MANUFACTURER:

Caltag Laboratories, Inc. 1849 Old Bayshore Highway Suite 200 Burlingame, CA 94010 (800) 874-4007

NAME OF CONTACT PERSON:

Robert C. Johnson Executive Vice President Caltag Laboratories, Inc.

DATE OF PREPARATION OF SUMMARY:

October 1, 1996

TRADE NAME OF THE DEVICE:

Caltag CD19 R-PE, CD19 TRI-COLOR Mouse Monoclonal Antibodies To Human Cell Surface Antigens by Flow Cytometry

COMMON NAME:

Caltag CD19 R-PE, CD19 TRI-COLOR Monoclonal Antibody

CLASSIFICATION NAME:

Automated Differential Cell Coulter (21 CFR 864.5220)

LEGALLY MARKETED DEVICE (PREDICATE DEVICE) TO WHICH THE MANUFACTURER IS CLAIMING SUBSTANTIAL EQUIVALENCE:

Caltag CD19 R-PE Monoclonal Antibody to Human Cell Surface Antigens is substantially equivalent to the Coulter CD19 RD1 Monoclonal antibody for invitro diagnostic use.

Caltag CD19 TRI-COLOR Monoclonal Antibody to Human Cell Surface Antigens is substantially equivalent to the Coulter CD19 FITC and CD19 RD1 monoclonal antibodies for in-vitro diagnostic use.

DESCRIPTION OF THE DEVICE:

INTENDED USE OF THE DEVICE:

CALTAG CD19 R-PE and CD19 TRI-COLOR are fluorochrome conjugated monoclonal antibody reagents that may be used to enumerate CD19+ lymphocytes in human peripheral blood by flow cytometric methods.

SUMMARY OF THE TECHNICAL CHARACTERISTICS OF THE MANUFACTURER'S DEVICE COMPARED TO THE PREDICATE DEVICE:

No.	Item	Caltag Antibodies	Coulter Antibodies	Comparison
1.	Intended Use	Flow Cytometry	Flow Cytometry
Immunofluorescence	Substantially
equivalent
2.	Specificity	CD19	CD19	Substantially
equivalent
3.	Target cell	B lymphocyte	B lymphocyte	Substantially
equivalent
4.	Chemical form	Monoclonal
antibody	Monoclonal
antibody	Substantially
equivalent
5.	Fluorochromes	R-PE,
TRI-COLOR	FITC,
RD1	Substantially
equivalent
6.	Available forms	FITC liquid, PBS
PE liquid, PBS
TRI-COLOR liquid, PBS	lyophilized
liquid, PBS
not available	Substantially
equivalent
7.	Sample prep.
methods	whole blood	whole blood	Substantially
equivalent
8.	Expected values
from this study (n=155)	R-PE 5-21%
TRI-COLOR 4-24%	4-21% (RD1)
3-23% (FITC)	Substantially
equivalent

Comparisons of Caltag CD19 and Coulter CD19 Monoclonal Antibodies

NON CLINICAL TESTS SUPPORTING A DETERMINATION OF SUBSTANTIAL EQUIVALENCE:

EXPECTED VALUE DATA

Blood samples were collected from a total of 155 apparently healthy normal donors in an age range of 16 to 72 with a mean age of 41. Samples were collected and analyzed in each of three independent laboratories. An approximately equal number of males and females were collected and analyzed in each laboratory.

The normal donor population included members of differing ethnic origins, including adult Caucasian, Black, Oriental and Hispanic.

Donors in geographically diverse areas of the United States, including the Western, Eastern and SouthCentral regions, participated in this study. Blood samples collected from each donor were stained with the CALTAG CD19 R-PE and CD19 TRI-COLOR monoclonal antibodies.

Summary of expected values for CALTAG CD19 monoclonal antibodies for all normal donors:

| procedure | mean
% positive | S.D.
$\pm$2 S.D. | Range | n |
|----------------|--------------------|-----------------------|-------|-----|
| CD19 R-PE | 13.0 | 4.2 | 5-21 | 155 |
| CD19 TRI-COLOR | 13.9 | 5.0 | 4-24 | 155 |

SPECIFICITY DATA

Blood samples were obtained from healthy normal donors of Caucasian, Black, Hispanic and Oriental ethnic origins. Samples of each donor were stained with CALTAG CD19 R-PE and CD19 TRI-COLOR monoclonal antibodies. Cells contained in the lymphocyte, monocyte and granulocyte regions were selected for analysis. Separate samples from the same donors were prepared for analysis of red blood cells and platelets and stained with each of the CALTAG monoclonal antibodies.

CD19 R-PE

| Ethnic

Origin	Lymph.	Mono.	Gran.	Plt.	RBC
Caucasian	18.0	0.6	0.9	0.5	0.5
Caucasian	13.3	1.1	0.8	0.3	0.7
Hispanic	12.2	0.7	0.8	0.4	1.0
Oriental	11.2	1.6	1.3	0.4	0.5
Black	14.6	0.0	0.5	0.6	0.9
Mean	13.9	0.8	0.9	0.4	0.7
± 1 S.D.	2.6	0.6	0.3	0.1	0.2

CD19 TRI-COLOR

| Ethnic

Origin	Lymph.	Mono.	Gran.	Plt.	RBC
Caucasian	18.3	0.0	1.0	0.3	0.4
Caucasian	12.1	0.2	1.1	0.4	0.1
Hispanic	11.6	0.2	0.3	0.2	0.7
Oriental	11.0	1.0	0.9	0.3	0.2
Black	12.0	0.7	0.9	0.4	0.2
Mean	13.0	0.4	0.8	0.3	0.3
$\pm$ 1 S.D.	3.0	0.4	0.3	0.1	0.2

Specific and/or nonspecific antibody Fc binding to monocytes in a patient sample can be excluded by proper gating on lymphocytes on the flow cytometer.

REPRODUCIBILITY DATA (INTRA-LAB)

Intra-lab reproducibility for the CALTAG CD19 R-PE and CD19 TRI-COLOR conjugated monoclonal antibodies was determined by performing 10 replicated determinations for each antibody in each of three ranges; high, medium and low. Thus, a total of 30 determinations were performed for each form of CD19. In this manner, reproducibility was demonstrated throughout the entire measuring range.

The 10 determinations for each range were performed by the staining, processing and analysis of 10 separate samples. Lymphocytes were selected for the analysis of percent cells stained in each of the three ranges.

To perform this study, anticoagulated blood was obtained from an abnormal donor expressing a high percentage of CD19+ cells. Mid range and low range samples were obtained by adding known CD19- cells in appropriate ratios, while maintaining approximately the same total cell concentrations for the three ranges.

The study was performed in each of three independent laboratories, in the manner that each laboratory obtained, stained and analyzed separate blood samples. The following data are representative:

| procedure | Level | mean
% positive | S.D. | % CV | n |
|-------------------|-------|--------------------|------|------|----|
| CD19 R-PE | high | 66.6 | 0.4 | 0.5 | 10 |
| | mid | 46.7 | 0.8 | 1.6 | 10 |
| | low | 14.9 | 0.6 | 4.3 | 10 |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19
TRI-COLOR | high | 65.4 | 0.7 | 1.0 | 10 |
| | mid | 46.1 | 0.6 | 1.3 | 10 |
| | low | 15.5 | 0.4 | 2.7 | 10 |
| | | | -6- | | |
| SITE 1 | | | | | |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19 R-PE | high | 84.7 | 4.4 | 5.2 | 10 |
| | mid | 70.4 | 1.2 | 1.8 | 10 |
| | low | 42.7 | 3.2 | 7.6 | 10 |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19
TRI-COLOR | high | 86.7 | 1.0 | 1.2 | 10 |
| | mid | 70.9 | 1.3 | 1.9 | 10 |
| | low | 42.7 | 0.9 | 2.1 | 10 |
| SITE 2 | | | | | |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19 R-PE | high | 83.9 | 1.5 | 1.7 | 10 |
| | mid | 71.1 | 2.8 | 3.9 | 10 |
| | low | 42.5 | 1.9 | 4.6 | 10 |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19
TRI-COLOR | high | 85.3 | 2.2 | 2.6 | 11 |
| | mid | 65.7 | 3.1 | 4.8 | 9 |
| | low | 32.6 | 2.0 | 6.0 | 10 |
| SITE 3 | | | | | |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19 R-PE | high | 87.5 | 0.6 | 0.7 | 10 |
| | mid | 69.9 | 0.8 | 1.1 | 10 |
| | low | 38.8 | 1.6 | 4.2 | 10 |
| procedure | Level | mean
% positive | S.D. | % CV | n |
| CD19
TRI-COLOR | high | 85.3 | 0.9 | 1.0 | 10 |
| | mid | 66.1 | 1.0 | 1.5 | 10 |
| | low | 30.7 | 2.4 | 7.9 | 10 |

REPRODUCIBILITY, (INTER-LAB)

Inter-lab reproducibility for the CALTAG CD19 R-PE and CD19 TRI-COLOR conjugated monoclonal antibodies was determined by performing 10 replicated determinations for each antibody in each of three ranges; high, medium and low. Thus, a total of 30 determinations were performed for each form of CD19. In this manner, reproducibility was demonstrated throughout the entire measuring range.

The study was performed in each of three laboratories. All laboratories stained and analyzed blood samples from the same blood donors. Lysed unstained samples containing cells in the appropriate ranges were prepared by one of the participating laboratories for staining and analysis in each of the laboratories. The following data were obtained:

CLINICAL TESTS SUPPORTING A DETERMINATION OF SUBSTANTIAL EQUIVALENCE:

CORRELATION DATA

The correlation study was performed on 175 donors, including 155 normal and 20 abnormal donors.

Comparison of the CALTAG CD19 R-PE conjugated monoclonal antibody with the Coulter CD19 RD1 conjugated monoclonal antibody:

| procedure | mean %
positive | r2
value | slope | Y
intercept | n |
|-----------|--------------------|-------------|-------|----------------|-----|
| CD19 R-PE | 16.4 | 97.7 | 0.92 | 1.30 | 175 |
| CD19 RD1 | 16.2 | | | | |
| CD19 R-PE | | | | | |

y = 1.30 + 0.92x Linear regression

Comparison of the CALTAG CD19 R-PE conjugated monoclonal antibody with the Coulter CD19 FITC conjugated monoclonal antibody:

| procedure | mean %
positive | r2
value | slope | Y
intercept | n |
|-----------|--------------------|-------------|-------|----------------|-----|
| CD19 R-PE | 16.4 | 96.3 | 0.93 | 0.69 | 175 |
| CD19 FITC | 16.7 | | | | |

CD19 R-PE

Linear regression y = 0.69 + 0.93x

Comparison of the CALTAG CD19 TRI-COLOR conjugated monoclonal antibody with the Coulter CD19 RD1 conjugated monoclonal antibody:

| procedure | mean %
positive | r²
value | slope | Y
intercept | n |
|-------------------------------------|--------------------|-------------|-------|----------------|-----|
| CD19 TRI-COLOR | 17.1 | 96.7 | 0.92 | 2.14 | 175 |
| CD19 RD1 | 16.2 | | | | |
| CD19 TRI-COLOR
Linear regression | $y =2.14 + 0.92x$ | | | | |

Comparison of the CALTAG CD19 TRI-COLOR conjugated monoclonal antibody with the Coulter CD19 FITC conjugated monoclonal antibody:

procedure	mean % positive	r² value	slope	Y intercept	n
CD19 TRI-COLOR	17.1	97.4	0.94	1.36	175
CD19 FITC	16.7
CD19 TRI-COLOR
Linear regression	$y = 1.36 + 0.94x$

Comparison of the CALTAG CD19 TRI-COLOR conjugated monoclonal antibody with the CALTAG CD19 R-PE conjugated monoclonal antibody:

procedure	mean % positive	r² value	slope	Y intercept	n
CD19 TRI-COLOR	17.1	97.6	0.99	-0.56	175
CD19 R-PE	16.4
CD19 TRI-COLOR
Linear regression	$v = -0.56 + 0.99x$

BIBLIOGRAPHY

Hsu S., Cossman J., Jaffe E.; Lymphocyte subsets in normal human lymphoid tissues. Am. J. Clin. Path. 80:21-30, 1983. 1.
Morimoto C., Levin N.L., Distaso J.A., et al: The cellular basis for the induction of antigen-specific T8-suppressor cells. 2. Eur. J. Immunol. 16:198-204, 1986.
1. Dorken B., Moller P., Pezzutto A., Schwarz-Albiez R., Moldenhauer G., B-cell antigens: CD19, in Fourth International Workshop and Conference On Human Leucocyte Differentiation Antigens, pp 34-36, Vienna, 1989.
Piruccello S.J., Johnson D.R., Reagents for flow cytomaty: Monoclopalic cell anigens, in Flow Cyonery And 4. Clinical Diagnosis, pp 56-78, pub. American Society of Clinical Pathologists, 1994.
5 Shields J.G., Righty K.P., Callard R.E., Regulation of human B cell prolification by the CD19 cell-surface glycoprotein, in Fourth International Workshop and Conference On Human Leucocyte Differentiation Antigens, pp 40-43, Vienna, 1989.
Nadler L.M., in Leukocyce Typing II, Volume 2, B cel/Leukemix Panel Workshop:Summary and Comments, Chapter 1:2-20, Springer 6. Verlag, New York, 1986.
1. Wedgwood R.I., X-linked agammaglobulinemia, in CRC Handbook Series In Clinical Laboratory Science, CRC Press, West Palm Beach Florida, pp 41-50, 1978.
Pearl E.R., Vogler L.B., Okos A.J. et al, B lymphocyce precursors in bone marrow. An analysis of normal individuals and patients with 8. antibody-deficiency states,
- J. Immunol. 120:1169-175, 1978.
Spickett G.P., Webster A.D., Farrant J., Cellular abnormalities in common variable immunodeficiency, 9.
Immunodefic. Rev. 2:199-219, 1990.
1. Small T.N., Keever C., Collins N. et al, Characterization of B cells in severe combined immunodeficiency disease, Hum. Immunol. 25:181-193, 1991.
1. Goldstein R., Laguire L.C., Douglas J. et al, Systematosus and common variable panhypogammaglobulinemia. Theoretical and practical considerations, Fed. Proc. 29:1606-1611. 1985.
1. Lokea M.L., Brosnan N.N., Back B.A., Aut K.A., Establishing opimal lymphocyce gates for immunophersonyping for flow cyometry. Cytometry 11:453-459, 1990.
Guidelines for the Performance of CD4+ T-Cell Determinations in Persons with Human Immundeticiency Virus Infection, Morbidity And 13. Mortality Weekly Report (MMWR), Volume 41/No. RR-8, May 8, 1992.
1. Nicholson J.K.A., Green T.A. and Collaborative Laboratories, Selection of anticoagulans for lymphocyce immunophenotyping. J. Immunol. Methods 165:31-35, 1993 .
ા રા Tennant J.R., Evaluation of the Trypan Blue technique for determination of cell viability, Transplanation 2:685-694, 1964.
1. Koepke J.A., Landay A.I.: Precision and Accuracy of Absolute Lymphocyte Counts,
Clin. Immunol, and Immunopath, 52:19-27, 1989.
1. Brown M.C., Hoffman R.A., Kirchanki S., Controls for flow cyometers in hematology and cethular immunology, Ann. N.Y. Acad. Sci. 468:93-103. 1986.
1. Durrand R.E., Calibration of flow cytometer detector systems, Cytomery 2:192-193, 1981.